RECORD: Harmer, S. F and W. G. Ridewood eds. 1910. Memorials of Charles Darwin: a collection of manuscripts portraits medals books and natural history specimens to commemorate the centenary of his birth and the fiftieth anniversary of the publication of "The origin of species" 2d edition. British Museum (Natural History). Special guide No. 4.

BY a coincidence rare in the records of previous celebrations, the
year 1909 is at the same time the hundredth anniversary of the birth of
a great man and the fiftieth anniversary of the completion of his
greatest work. Charles Robert Darwin was born in 1809, and the "Origin
of Species" was published in 1859. In recognition of this double motive
for signalising the present year, the Trustees directed that an
exhibition should be prepared of specimens, autograph letters, books
and portraits relating to Darwin.

It is not the part of a Museum to endeavour to decide whether the
share ascribed by Darwin to the operation of Natural Selection in the
evolution of animals and plants was or was not correctly estimated.
Some of the leading Biologists of the present day are in this respect
even more Darwinian than Darwin himself, while others attribute less
importance than he did to the principle of Natural Selection. But
whatever view may be taken of this question, the magnitude of Darwin's
influence on contemporary thought can hardly be overestimated, and the
desirability of illustrating his teaching can scarcely be questioned.

Without necessarily implying any expression of opinion on
controversial matters, it has thus seemed best to illustrate some of
Darwin's arguments by means of specimens, using as far as possible the
species to which he himself referred in his writings, and in some cases
the material which actually passed through his hands. In this part of
the Exhibition, the attempt is made to place before the public a few
selected examples, to enable those who read Darwin's works to see some
of the evidence on which he relied. The "Origin of Species" was
naturally chosen in the first instance for illustration: though
references to other works are given here and there. Possibly some few
of the illustrations may not be well known even to experienced
Zoologists and Botanists. It should be understood that the

exhibition makes no claim to be regarded as more than a very small
selection, not to be taken as a complete illustration of Darwin's work.

Another set of specimens has a more personal interest, since they
were collected by Darwin or are known to have been studied by him. With
these may be noticed some of Darwin's apparatus, and a glance will show
how simple were the tools with the aid of which his most famous
observations were made.

The selection of autograph letters includes some of special
interest. Attention may be directed to Nos. 1, 3, 2, in the catalogue,
consisting of Professor Henslow's invitation to Darwin to take part in
the Beagle voyage, of Darwin's summary of his father's
objections to the proposal, and of Josiah Wedgwood's reply to those
objections. The characteristic and remarkable letter from Huxley (No. 18), written immediately after his first perusal of
the "Origin of
Species," is one that specially deserves attention.

The exhibition further contains a number of portraits of Darwin, one
or two medals founded in his honour, and copies of his printed books.
With these are shown a few works, such as those by Haeckel, Weismann
and others, which have special reference to Darwin's theories. It will
readily be understood that these do not pretend to constitute more than
a fraction of the enormous literature that has sprung into existence as
the result of the publication of the "Origin of Species."

The greater number of the specimens and books, and a few of the MSS.
are the property of the British Museum. For other specimens, as well as
for most of the MSS. and portraits and for a few of the books, the
Museum is indebted to the owners whose kindness in lending the relics
is acknowledged in the pages of this Guide. Special thanks are due to
the Council of the Royal College of Surgeons for their loan of the
fossils collected by Darwin in South America; and to Mr. William
Darwin, Professor Sir George Darwin, K.C.B., F.R.S., Mr. Francis
Darwin, F.R.S., Major Leonard Darwin, and Mr. Horace Darwin, F.R.S.,
for various objects connected with their father's life. To Mr. J. C.
Simpson, of Emmanuel College, Cambridge, the Museum is specially
indebted for having made arrangements which facilitated the borrowing
of some of the objects which were exhibited at Cambridge in June.

In the following catalogue of the exhibits, the source from which
the object was obtained is indicated in the case of every specimen or
paper borrowed for the occasion. The absence of any such acknowledgment
may be taken to imply that the object belongs to the British Museum.

The frontispiece of this Guide is a reduced reproduction of a
photograph taken about 1868 by Mrs. J. M. Cameron, Freshwater, Isle of
Wight, lent for the purpose by Mr. Francis Darwin, and published by
kind permission of Mr. John Murray. The other plate, facing page 7, is
a photographic reproduction of the statue of Darwin, by Sir J. E.
Boehm, R.A., on the main staircase at the North end of the Central Hall.

The arrangement of the specimens for exhibition and the preparation
of this Guide-book are the work of Dr. W. G. Ridewood.

SIDNEY F. HARMER,

Keeper of Zoology.

July, 1909.

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PREFACE TO THE SECOND
EDITION.

THE fact that a Second Edition of this Guide-book is required less
than six months after the publication of the First Edition is evidence
of the interest that has been taken in the Darwin Exhibition.

A Table of Contents has been added, and a few verbal alterations
have been made by Dr. W. G. Ridewood, the author of the First Edition.

CHARLES ROBERT DARWIN was born at Shrewsbury on February 12th, 1809.
He was the son of Robert Waring Darwin, a Doctor of Medicine of
Shrewsbury, and grandson of Dr. Erasmus Darwin, poet and philosopher,
probably best known as the author of "Loves of the Plants." On leaving
the Grammar School at Shrewsbury in October, 1825, Darwin went to
Edinburgh University to study medicine. His father, however, perceiving
that he did not relish the idea of becoming a physician, proposed that
he should become a clergyman, and with that intent Darwin went to
Cambridge early in 1828, and remained there three years. He left
Cambridge to join the Beagle as naturalist of the
expedition,
and was away from England from December, 1831 to October, 1836.

On his return from the Beagle voyage Darwin settled in
Cambridge, and in March, 1837, took lodgings in Great Marlborough
Street, London, where he stayed two years till his marriage in January,
1839. He married his cousin, a grand-daughter of Wedgwood, the famous
potter. He had by this time finished the "Journal" of the Beagle voyage
(republished later as "A Naturalist's Voyage Round the World"), and
was preparing his "Geological Observations," which were produced in
the form of three books, in 1842, 1844 and 1846 respectively; and he
was also engaged in editing the "Zoology of the Voyage of H.M.S. Beagle,"
which appeared in five parts between 1839 and 1843. He lived in Upper
Gower Street from January, 1839, to September, 1842, when he moved to
Down, in Kent, where he remained for the rest of his life. In October,
1846, he began his study of the Cirripedia, upon which he wrote four
volumes (1851-1854).

The idea of selection by nature had been working in his mind since
the voyage of the Beagle. The succession of the
great
extinct
Edentates of the Pampas of Argentina by the modern Armadillos, and the
peculiarities of the fauna of the Galapagos Archipelago, the
productions of each island of which differ slightly

from those of the other islands, pointed to species being capable of
modification, in a gradual manner. But he admitted to being puzzled by
structural features specially adapted to habits and surroundings, such
as the modification of the feet and tail-feathers of the woodpecker for
climbing trees, and of hooks and plumes of seeds for dispersal. He
commenced to accumulate a vast mass of evidence to show the extent to
which artificial selection by man has resulted in the production of
varieties among domesticated animals and cultivated plants, and in
1838, after reading the "Essay on the Principles of Population," by
Thomas Malthus, in which the struggle for existence among human beings
is clearly set forth, he conceived the idea that a similar struggle
among animals and plants had led to the extinction of those individuals
which were least fitted to their environment, and that by
differentiation, resulting from the action of different environmental
conditions on organisms at first similar, new species had come into
existence. In June, 1842, he first committed his ideas on the subject
to paper, and this first draft, of thirty-five pages, he rewrote and
expanded to 230 pages in 1844.

When it became known in 1858 that Alfred Russel Wallace had
independently arrived at somewhat similar conclusions, it was arranged
by Lyell and Hooker that Darwin and Wallace should expound their views
jointly at a meeting of the Linnean Society. The title of the joint
paper was "On the Tendency of Species to form Varieties; and on the
Perpetuation of Varieties and Species by Natural Means of Selection."

In the following year Darwin produced his "Origin of Species," a
book which in his autobiography of 1876 he admits to be the chief work
of his life. The first edition (1250 copies) was sold out on the day of
its production, November 24th, 1859, and Darwin immediately set to work
to revise the book for a second edition, which appeared on January 7th,
1860, and consisted of 3000 copies. The sixth and last edition was
published in January, 1872, and of this numerous reprints have been
issued.

In 1860 Darwin began arranging his notes for the "Variation of
Animals and Plants under Domestication," a work which appeared in 1868.
In 1862 he published his book on the "Fertilisation of Orchids," and
afterwards his papers, read before the Linnean Society, on dimorphism
in Primula and trimorphism in Lythrum. His paper
on
"Climbing Plants" in 1865 was reproduced in book form in 1875.

He published the "Descent of Man " in 1871, the "Expression of the
Emotions" in the autumn of 1872, "Insectivorous Plants"

in 1875, the "Effects of Cross and Self Fertilisation in the
Vegetable Kingdom" in 1876, the "Different Forms of Flowers on Plants
of the Same Species" in 1877, the "Power of Movement in Plants" in
1880, and the "Formation of Vegetable Mould through the Action of
Worms" in 1881.*

Darwin was awarded the Royal Medal of the Royal Society in 1853, and
the Copley Medal in 1864, and the Wollaston Medal of the Geological
Society in 1859. He died at the age of 73 on April 19th, 1882, and was
buried in Westminster Abbey.

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* A complete list of Darwin's books and his
contributions to scientific periodicals is to be found at the end of
the third volume of the "Life and Letters of Charles Darwin," by his
son, Francis Darwin, 1887.

The special cases containing the specimens illustrative of Darwin's
life and work are indicated by pale green labels. To facilitate the
finding of any particular case they are numbered in as consecutive a
manner as their positions will permit. It is not recommended, however,
that the visitor should proceed from case to case in the numerical
sequence; it is intended that the exhibits shall be reviewed in the
order in which they are referred to in the descriptive "List of
Exhibits" (p. 7 et seq.).

Case 1. A large frame on the right-hand side of
the Eastern* arch
leading to the North Hall, containing Manuscripts of Darwin, — pp.
7-11,
Nos. 1-24.

Case 2. The North wall-case of Bay VI,† containing
a series of
Burrowing Animals, an illustration of "adaptive modification." — p. 31,
No. 161.

Case 3. An upright table-case on the East side of
the main
staircase, containing Manuscripts and Books by Darwin, or connected
with Darwin's life and work. — pp. 11-18, Nos. 25-88.

Case 4. An upright, shallow case set obliquely
across the entrance
of Bay VI, containing Medals and Portraits of Darwin, and other
photographs and sketches of interest in connection with Darwin's life
and work. — pp. 19-21, Nos. 89-115.

Case 5. A frame on the North side of the arch of
Bay VII, containing
a series of feathers of the Peacock illustrating "gradation in
ornament." ("Descent of Man." Chap. xiv.) — p. 26, No. 129.

Case 6. The North wall-case in Bay VII, containing
at the left-hand
end and on the floor specimens collected by Darwin, or studied by him;
and in the remainder of the case specimens illustrating passages in
Darwin's books. — pp. 23-32, Nos. 116-140 and 148-170.

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* The entrance to the Museum is at the South end
of the Central Hall, and the main staircase is at the North end;
the side of the Hall to the right of the visitor on entering is the East.

† The Bays or Recesses around the Central Hall are
denoted by numerals. On the East side, the Bay nearest the Huxley
statue is No. X, and that by the side of the main staircase is No. VI.

Case 8. A small black case containing a
microscope, set on a table
at the end of Bay VII. In this case are shown specimens of avicularia
and vibracula of Polyzoa. — pp. 33-34, No. 171.

Case 9. The South wall-case in Bay VII, containing
a series of
specimens illustrating passages in Darwin's books, more particularly
the "Origin of Species"; a continuation of the series shown in Case 6. — pp. 28-29, Nos. 141-147 and pp. 34-41, Nos. 172-204.

Case 10. A frame on the South side of the arch of
Bay VII,
containing a series of feathers of the Argus Pheasant. ("Descent of
Man." Chap. xiv.) — p. 26, No. 129.

Case 11. A black table-case set across the
entrance to Bay VIII,
containing the fossil remains of extinct Mammals collected by Darwin in
South America in 1833. — pp. 21-22.

Case 12. The North wall-case in Bay IX, containing
a series of
specimens in continuation of those shown in Cases 6 and 9. — pp. 41-50,
Nos. 205-251.

Case 13. A horizontal table-case in Bay IX,
containing on the one
side specimens of Cirripedia or Barnacles studied by Darwin during the
years 1846-1854, and described in his monograph on that group of
animals; and on the other side specimens of Corals collected by Darwin
at Keeling Island in 1836. — pp. 22-23.

Case 14. An upright case near the foot of the
staircase, containing
a series of Desert Animals, showing the uniform sandy coloration which
renders these animals so little conspicuous in their natural
surroundings. — p. 38, No. 187.

Case 17. An upright case containing typical
specimens of the Carrion
Crow (Corvus corone) and Hooded Crow (Corvus
cornix), and
a map showing the distribution of each species; also examples of Birds
exhibiting characters intermediate between those of the two species,
obtained from a region where both species occur and interbreed. The
same case contains a series of Goldfinches exhibiting characters
intermediate between those of the Common Goldfinch

(Carduelis elegans) and the
Himalayan Goldfinch (Carduelis
caniceps), obtained from a region where the
geographical areas of
the two species overlap. — p. 26, No. 132.

Case 18. An upright case containing in the upper
part the wild Rock
Pigeon (Columba livia), and below examples of the
principal
breeds of domestic Pigeon, illustrating the great variation which a
species may exhibit in a state of domestication by careful selective
breeding. ("Animals and Plants under Domestication." Chaps. v and
vi.) — p. 25, No. 128 and p. 26, No. 131.

Case 19. A table-case near the Owen statue,
containing models and
specimens illustrating the Fertilisation of Flowers. ("Fertilisation
of Orchids," 1862, and "Cross and Self Fertilisation of Flowers,"
1876.) — p. 50.

Case 21. An upright case containing examples of
the Red Jungle Fowl
of India, and specimens of the principal breeds of domestic Fowl,
illustrating the great variation which a species may exhibit in a state
of domestication by careful selective breeding. ("Animals and Plants
under Domestication." Chap. vii.) The case also contains a series of
wild and domestic Canaries. — p. 26, No. 130.

Case 22. An upright case containing Ruffs and
Reeves (Pavoncella
pugnax), showing the
remarkable difference in the plumage of the
two sexes, and the variability of that of the male, during the breeding
season. — p. 29, No. 148.

Case 23. An upright case containing Drakes and
Ducks (Anas
boscas), showing the
remarkable difference in the plumage of the
two sexes during the breeding season. — p. 29, No. 148.

Cases 24 and 25. Upright cases
containing Mammals and Birds from
Norway, illustrating the adaptation of the colour of the coat to that
of the natural surroundings, by virtue of which the animals are
rendered less conspicuous to their enemies, or to their prey. In Case 24 the animals are shown as they appear in summer; in
Case 25 as they
appear in winter. — p. 38, No. 187.

At the top of the first flight of stairs at the North* end of the
Central Hall, a sitting statue of Darwin executed by Sir J. E. Boehm,
R.A., as part of the "Darwin Memorial" raised by public subscription,
It was unveiled on June 9th, 1885, when an address was delivered on
behalf of the Memorial Committee by the late Professor Huxley, Pres.
R.S., to which His Majesty the King (then Prince of Wales),
representing the Trustees, replied. A photographic reproduction of the
statue faces this page.

MANUSCRIPTS.

In Case 1, a large frame on the right-hand side of
the Eastern arch
leading from the Central Hall to the North Hall:—

1. A letter, dated August
24th, 1831, from Henslow to
Darwin, inviting him to travel as naturalist on the Beagle.
Darwin
was eager to accept, but his father objected, in the terms set forth in
MS. No. 3 here shown. The objections were submitted
to Darwin's uncle,
Josiah Wedgwood, whose reply is here shown (No. 2).
Lent by Francis
Darwin, Esq., F.R.S.

2. A letter from Josiah
Wedgwood (second son of the
distinguished potter) to Darwin's father, which decided the latter to
allow his son to go on the Beagle expedition. Dated August
31st, 1831. Lent by Francis Darwin, Esq., F.R.S.

3. A manuscript by Charles
Darwin detailing his
father's objections to his going on the Beagle voyage. Lent
by
Francis Darwin, Esq., F.R.S. This paper was submitted to Josiah
Wedgwood, when his advice was solicited, and it is referred to in
Wedgwood's reply here shown (No. 2).
The objections are as follows:—

"1. Disreputable to my character as a Clergyman hereafter.

"2. A wild scheme.

"3. That they must have offered to many others before me the place
of Naturalist.

"4. And from its not being accepted there must
be some serious objection to the vessel or expedition.

4. Four pages of zoological
notes on Aplysia, Planaria, and Cleodora, made by Darwin
during the voyage
of the Beagle. They are dated February, 1832. Lent by
Francis
Darwin, Esq., F.R.S.

5. A list of the officers
and men of the Beagle,
dated
October, 1836, i.e., on the completion of the voyage.
Darwin's
name occurs at the top of the left-hand column. Lent by Francis Darwin,
Esq., F.R.S.

6. A letter from Darwin to
Owen, dated Thursday 28th,
36, Gt. Marlboro' St., referring to the return of the proof-sheets of
Owen's paper on Toxodon, which were submitted to
Darwin for
criticism. The date is probably 1837.

7. A letter from Darwin to
George R. Gray, of the
British Museum, thanking him for a copy of his book on the "Genera of
Birds," and expressing a hope that he would now be free to complete the
volume of the Beagle Birds left unfinished by John Gould.
The
date of the letter is probably 1840.

8. A letter from Darwin to
Owen referring to a
weathered Elephant's tooth and a tusk from Peru. Judging from the
address (12, Upper Gower Street) the date of the letter is between 1839
and 1842.

9. A letter from Darwin to
Daniel Sharp dealing with
foliation, cleavage, stratification, volcanic rocks, and other
geological matters. The letter bears the postmark November 2nd, 1846.

10. A hitherto unpublished
letter bearing the post-mark
August 2nd, 1843, written by Darwin to G. R. Waterhouse (afterwards of
the British Museum), and expressing his views as to what should be
aimed at in classifying animals and plants. He writes: "All rules for
a natural classification are futile until you can clearly explain what
you are aiming at. Until that is done I must protest against sameness
of country (as with the Monotremata) being used...I believe...that if
every organism which ever had lived or does live were
collected together (which is impossible, as only a few can have been
preserved in a fossil state), a perfect series would be presented,
linking all, say the Mammals, into one great, quite indivisible group."
Lent by C. O. Waterhouse, Esq.

11. A letter from Darwin to
Owen, saying that Captain
Sulivan, R.N., had arrived in London with six casks of fossil bones
from the southern part of Patagonia, and expressing a wish to examine
the bones with Owen, when they had been unpacked at the Royal College
of Surgeons Museum. Date probably between 1840 and 1850.

12. A letter from Darwin to
Owen, dated "Nov. 25th,
Down, Farnborough, Kent," asking for the loan of some Barnacles from
the College of Surgeons Museum. Date between 1846 and 1851.

13. A hitherto unpublished
letter, bearing the
post-mark July 27th, 1843, written by Darwin to G. R. Waterhouse
(afterwards of the British Museum). Darwin writes, in reference to a
discussion on classification:—"It has long appeared to me that the
root of the difficulty in settling such questions as yours—whether
number of species, etc., etc., should enter as an element in settling
the value or existence of a group—lies in our ignorance of what we are
searching after in our natural classification...According to my
opinion...classification consists in grouping beings according to
their...descent from common stocks...There is one caution...the great
doubt whether the groups which are now small may not have
been at some former time abundant, and you will admit fossil and recent
beings all come into one system...Perhaps if the Goatsucker and
Woodpecker were varied into very many genera, and very many species of
each, they would be looked on as orders equal to the Hawks, etc." Lent
by C. O. Waterhouse, Esq.

14. The first page of
Darwin's 1844 sketch of his
theory on the origin of species. The first clear conception of the
theory occurred to Darwin at the end of 1838, or the beginning of 1839,
but he did not set it out in writing till June, 1842. The 1842 draft
consisted of 35 pages, and this was rewritten and expanded to 230 pages
in the summer of 1844. The manuscript shown is the first page of the
1844 draft. Lent by Francis Darwin, Esq., F.R.S.

15. A letter from
Darwin to Owen, asking for a
specimen of Balanus glacialis from the College of Surgeons
Museum. The left-hand half of the letter is a personal one to Owen, the
right-hand half is a formal application which Owen might lay before the
Council of the College if the sanction of that body were necessary. The
date is probably 1852 or 1853.

16. A letter from Darwin to
S. P. Woodward, of the
British Museum, best known as the author of the "Manual of the
Mollusca."

In this letter Darwin expresses his inability to accept the view
(Carpenter's, 1844) that the Hippuritidæ are in any way a connecting
link between the Oysters and the Barnacles. Date, May 6th, 1854. Lent
by B. B. Woodward, Esq.

17. A letter from Darwin to
S. P. Woodward, in which he
discusses the relative antiquity of volcanoes, and expresses his
disagreement with Von Buch's "elevation-crater-theory." The date is
about 1860. Lent by B. B. Woodward, Esq.

18. A letter from Huxley to
Darwin, dated November
23rd, 1859, in which he states that he has finished reading the
"Origin of Species," and expresses the pleasure that the new views have
given him. He advises Darwin not to be annoyed by the abuse which is
doubtless in store for him, and assures him that he can rely upon the
support of his friends. The letter is published in "Life and Letters
of Charles Darwin," by F. Darwin, Vol. ii, pp. 231-2. Lent by Francis
Darwin, Esq., F.R.S.

19. A letter from Darwin to
Owen, dated December 13th,
1859, referring to the "Origin of Species," which had appeared during
the preceding month. The letter is published in "The Life of Richard
Owen," by R. Owen, 1894, Vol. ii, pp. 90-91.

20. A letter from Darwin to G. R. Waterhouse,
of the British Museum, concerning "the eldest son of Sir J. Lubbock,"
the present Lord Avebury, whom he wished to propose for membership of
the Entomological Society. Date, 1850.

21. A letter written by
Darwin in 1854 or 1855 to
William Harris, of Charing, Kent, from whom he had borrowed some
Cirripedes to study when writing his monograph on that group of
animals. Lent by C. D. Sherborn, Esq.

22. A long letter from
Darwin to a correspondent whose
name does not appear on the letter, and who was evidently opposed to
the views expressed in the "Origin of Species." Darwin writes that as
the undulatory theory of light is based on analogy with the passage of
sound waves through air, so he defends his theory of natural selection
by analogy with artificial selection. In the latter part of the letter
he states that he did not discuss "alternation of generations,"
because he looked upon the non-sexual reproduction as a process of
gemmation during a larval stage, and that the life-history as a whole
does not differ essentially from one in which there is no alternation.
The date of the letter is probably 1861.

Down, Farnborough, Kent," referring to negotiations for the purchase
of a skeleton of the Sabre-toothed Tiger, Machairodus,
offered
by Señor F. Muniz, and to a translation into English of a Spanish
paper on these remains.

24. A letter from Darwin to
Samuel Butler thanking him
for a copy of a work of his, probably either "Erewhon" (1872) or "The
Fair Haven" (1873), both of which were published under the initials
"S. B." Darwin states that he would not have suspected Butler as the
author of the book. The date of the letter is probably 1872 or 1873.

MANUSCRIPTS (continued), BOOKS,* ETC.

In Case 3, a large
table-case standing on the Eastern side of the
main staircase:—

25. An early note-book of
Darwin's containing
observations made when he was at Edinburgh in March 1827. On the
right-hand page shown he describes his discovery of the young of the
Skate-leech, Pontobdella muricata. Lent by Francis
Darwin,
Esq., F.R.S.

26. Darwin's pocket-book,
containing notes made in
September, 1834, while at Santiago, during the voyage of the Beagle.
Most of the notes are geological, but some refer to the natural
history of the country. Lent by Francis Darwin, Esq., F.R.S.

27. Darwin's pocket-book,
containing notes on the
geological structure of the Coquimbo valley made after the arrival of
the Beagle at Valparaiso in July, 1834. The notes are in
pencil throughout, and each page is scored across, presumably to denote
that a copy had been made. Lent by Francis Darwin, Esq., F.R.S.

28. Letters written by
Darwin during the voyage of the Beagle to Professor Henslow, who read them at a meeting of the Cambridge
Philosophical Society in November, 1835, and had them printed for
distribution among the members of the Society.

29. Twenty-four pages of
notes of Insects caught during
the voyage of the Beagle. The corrections and
additions are
in
Darwin's handwriting. The capture of live beetles in the sea at a
distance of seventeen miles from land, here recorded, is published in
the "Naturalist's Voyage round the World," p. 159 of the 1882 edition.

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* Only a selected series of Darwin's books and
scientific papers is
here shown; a complete list of his writings is to be found at the end
of Vol. iii of the "Life and Letters of Charles Darwin," by F. Darwin,
1887. A large proportion of the books in Case 3 are
books on Darwinism,
and other writings inspired by Darwin's work.

30. Microscope used by
Darwin on the Beagle.Lent
by Sir George H. Darwin, K.C.B., F.R.S.

31. Microscope used by
Darwin. Lent by Sir George H.
Darwin, K.C.B., F.R.S.

32. Simple microscope used
by Darwin on the Beagle.
Lent by Sir George H. Darwin, K.C.B., F.R.S.

33. (At the top of the
case). Dissecting microscope
used by Darwin. Lent by Francis Darwin, Esq., F.R.S.

34. A volume of notes on
Reptiles, etc., made on the Beagle expedition, those on the left-hand page shown being in Darwin's
handwriting. Date, September, 1835; locality, Galapagos Islands. The
first note on the page has reference to the Sea Iguana, Amblyrhynchus
cristatus, a lizard of which Darwin gives a figure in the
"Naturalist's Voyage round the World," p. 385. (A stuffed specimen of
the lizard is shown in Case 12.)
Of further interest is the pencil note
on the right-hand page allotting specimen 1315 another Amblyrhynchus,
for dissection by Mr. Owen.

35. Darwin's "Naturalist's
Voyage round the World" or
"Journal of Researches into the Natural History and Geology of the
Countries visited during the Voyage of H.M.S. Beagle round
the
World, under the command of Captain Fitzroy, R.N.," 1882. (The original
appeared in 1839 in Vol. iii of the "Narrative of the Surveying
Voyages of H.M.S Adventure and Beagle." It was
issued
separately as "Journal of Researches, etc.," and a second edition
appeared in 1845, and was re-issued in 1860 with a postscript.) The
book is opened at pp. 384-5, showing a figure of the Sea Iguana, Amblyrhynchus
cristatus, mentioned in the MS. above.

36. "Zoology of the Voyage
of H.M.S. Beagle,"
edited
and superintended by Charles Darwin:

Part I.

Fossil Mammalia, by
Richard Owen, 1840.

Part II.

Mammalia, by G. R.
Waterhouse, 1839.

Part III.

Birds, by John Gould
(and G. R. Gray), 1841.

Part IV.

Fish, by the Rev.
Leonard Jenyns, 1842.

Part V.

Reptiles, by Thomas
Bell, 1843.

37. Darwin's "Structure and
Distribution of Coral
Reefs"; being Part I of the Geology of the Voyage of the Beagle.
London,
1842. (Republished with Parts II and III in 1851; Second Edition, 1874;
Third Edition, 1889.)

visited during the Voyage of H.M.S. Beagle"; being Part II
of the Geology of the Voyage of the Beagle. London,
1844.
(Republished with Parts I and III in 1851; Second Edition, with Part
III, 1876.)

39. Darwin's "Geological
Observations on South
America"; being Part III of the Geology of the Voyage of the Beagle.
London,
1846. (Republished with Parts I and II in 1851. Second Edition, with
Part II, in 1876.) The three fossils figured in the left top corner of
the plate shown are exhibited in Case 6.

40. Several pages in
Darwin's handwriting of an
abstract of Pallas's "Mémoire sur la variation des animaux" (Acta
Acad. Sci. Imp. Petropol., 1780). It is interesting as showing the kind
of abstracts Darwin made of the books that he read. Lent by Francis
Darwin, Esq., F.R.S.

41. Pallas's paper, "Mémoire
sur la variation des
animaux" (Acta Acad. Sci. Imp. Petropol., 1780), opened at pages 84 and
85 for comparison with the notes made by Darwin and shown in the
manuscript above.

42. A note-book of Darwin's,
dealing chiefly with
expression. It bears the date 1838, and the address 36, Great
Marlborough Street, and contains numerous references to information
supplied by his father in the course of conversation. Lent by Francis
Darwin, Esq., F.R.S.

43. A copy of questions on
cross-breeding drawn up by
Darwin for circulation among farmers and cattle-breeders. The questions
are twenty-one in number, and are printed with a wide margin for
replies. The copy is not dated, but since it is addressed from 12,
Upper Gower Street, the date of issue is probably about 1840.

44. Darwin's "Monograph of
the Sub-class Cirripedia,
with Figures of all the Species." The Lepadidæ, or Pedunculated
Cirripedes. London, 1851. (Ray Society.)

45. Darwin's "Monograph of
the Sub-class Cirripedia,
with Figures of all the Species." The Balanidæ, or Sessile
Cirripedes,
the Verrucidæ, etc. London, 1854. (Ray Society.)

47. A letter from Darwin to
Owen, dated July 17th,
1854, in reply to a letter from Owen complimenting him on his monograph
on the Cirripedia. The letter is published in "The Life of Richard
Owen," by R. Owen, 1894, Vol. i, pp. 407-8.

48. "The Life of Richard
Owen," by R. Owen, Vol. i, p.
408, showing the letter from Darwin to Owen, of which the original is
shown above.

49. Two selected pages of
Darwin's copy of his letter
to Prof. Asa Gray, dated September 5th, 1857, a letter which
constituted part of the paper "On the Tendency of Species to form
Varieties, and on the Perpetuation of Varieties and Species by Natural
Means of Selection," which was communicated to the Linnean Society by
Darwin and Wallace jointly on July 1st, 1858. The letter was published
in the Journal of the Linnean Society, Zoology, Vol. iii, No. 9, 1858
[1859], pp. 50-53 (see copy here shown), and was republished in "The
Darwin-Wallace Celebration" volume of the Linnean Society, 1908, pp.
95-98.

50. Journal of the Linnean
Society, Zoology, Vol. iii,
London, 1859. The copy is opened at pp. 50 and 51, showing the letter
from Darwin to Asa Gray, of which the original MS. is here exhibited.

51. "The Foundations of the
Origin of Species," being
Darwin's 1842 preliminary sketch of the Origin of Species, edited by
Francis Darwin, F.R.S., and printed by the Cambridge University Press,
1909. Copies of this book were presented by the Syndics of the
University Press to the delegates and other guests at the Cambridge
Darwin Commemoration, June 23rd, 1909.

52. Darwin's "On the Origin
of Species by means of
Natural Selection, or the Preservation of Favoured Races in the
Struggle for Life," London, 1859. (Second Edition, 1860; Third, 1861;
Fourth, 1866; Fifth, 1869; Sixth, 1872.) The copy shown is of the first
edition. Lent by J. C. Simpson, Esq.

53. A paper by Dr. W. C.
Wells, entitled, "An Account
of a Female of the White Race of Mankind, part of whose Skin resembles
that of a Negro," a paper in which he recognises the principle of
natural selection in the case of the different races of man, and
compares it with the improvement of the varieties of domestic animals
by selective breeding. The paper was read before the Royal Society in
1813, but was not published by that body; it appeared as part of Dr.
Wells's book on "Single Vision, Dew, Letter to Lord

Kenyon, etc.," in 1818 (the book here shown). The paper was
apparently unknown to Darwin at the time that he wrote the "Origin of
Species." In the "Historical Sketch" at the beginning of the sixth
edition of that work he gives a lengthy quotation from it, including
the passage here marked.

54. Note B of the Appendix
of Patrick Matthew's book on
"Naval Timber and Arboriculture," 1831, in which a reference to
Nature's method of elimination of the least fit is expressed in the
words—"those individuals who possess not the requisite strength,
swiftness, hardihood, or cunning falling prematurely without
reproducing...their place being occupied by the more perfect of
their own kind..." (p. 365). A similar statement occurs on p. 384, in
a section of the Appendix devoted to the adaptation of living things to
their environment.

Although Matthew's book was published in 1831, Darwin did not see it
till April, 1860, after the appearance of the second edition of the
"Origin of Species," when Matthew republished his views in the Gardener's
Chronicle. Darwin at once wrote to the Gardener's
Chronicle a
letter, in which occur the words, "I freely acknowledge that Mr.
Matthew has anticipated by many years the explanation which I have
offered of the origin of species, under the name of natural selection."

55. A copy of the first
edition of the "Vestiges of
the Natural History of Creation," published anonymously in 1844, and
attributed to various writers, but subsequently known to be the work of
Robert Chambers. The author writes (p. 222): "The idea which I form
of the progress of organic life upon the globe...is that the simplest
and most primitive type, under a law to which that of like-production
is subordinate, gave birth to the type next above it, that this again
produced the next higher, and so on to the very highest, the stages of
advance being in all cases very small—namely, from one species only to
another; so that the phenomenon has always been of a simple and modest
character." Since the book appeared after Darwin had rewritten and
expanded the first draft of his views upon the origin of species, it
cannot have influenced him much, but Darwin frankly admits,
nevertheless, in the "Historical Sketch" in the sixth edition of the
"Origin of Species," that the writer of the book "argues with much
force on general grounds that species are not immutable productions."

56. A letter written by
Darwin to Owen, giving the
reference to the page in Hearne's "Travels" in which mention is made
of

North American bears swimming in water and swallowing water-insects.
Owen criticised Darwin for suggesting that this habit of the bear might
in course of time lead to the evolution of a purely aquatic animal
"like a whale" (see p. 25 of Owen's Edinburgh Review article
here shown).

The letter also refers to a copy of Hunter's "Essays and
Observations" which he was expecting to receive from Owen. The printed
slip giving the address to which Darwin wished the book sent is
interesting as showing the methodical habits of the writer.

Judging from the date of Owen's criticism and the date of the
publication of Hunter's book, the letter was written in 1860.

57. Proof-sheets of the
hostile "Edinburgh Review"
article on the "Origin of Species," April 1860, found among the papers
of Sir Richard Owen after his death. The article was not signed, but it
was generally known to have been written by Owen.

58. Darwin's "On the Various
Contrivances by which
British and Foreign Orchids are fertilised by Insects, and on the Good
Effect of Intercrossing," London, 1862. (Second Edition, 1877.) Lent by
Dr. F. Du Cane Godman, F.R.S.

59. "Für Darwin," by Fritz
Müller,
Leipzig, 1864. (A
translation by W. S. Dallas was published in London, 1869, entitled
"Facts and Arguments for Darwin."). The book deals mainly with
Crustacea, and comprises a number of facts which support Darwin's
theory of natural selection.

60. "The Darwinian Theory of
the Transmutation of
Species," examined by a Graduate of the University of Cambridge,
London, 1867.

66. "Studien zur
Descendenz-Theorie," by August
Weismann, Leipzig, 1875-6. (A translation by R. Meldola was published
in London in 1882 under the title "Studies in the Theory of Descent.")

67. A page of Darwin's
manuscript of the "Expression
of the Emotions," Chapter vi. It has reference to the shedding of tears
and it shows the considerable amount of alteration to which the author
subjected his original draft before he was satisfied with it. The date
is probably about 1871. The copy of the "Expression of the Emotions"
which is shown by the side of the manuscript is opened at the page
where the particular passage occurs. Lent by Francis Darwin,
Esq., F.R.S.

68. Darwin's "Expression of
the Emotions in Man and
Animals." London, 1872. (Second Edition, 1873.) The copy is opened at
pp. 168-169, and the passage of which Darwin's manuscript is shown is
marked in the margin.

69. A copy of the First
Edition of the "Expression of
the Emotions in Man and Animals," 1872, open to show Plate I, with six
figures of crying children. Lent by Dr. F. Du Cane Godman, F.R.S.

83. "Essays on Evolution,
1889-1907," by E. B. Poulton, 1908. Lent
by the Oxford University Press.

84. "The Darwin-Wallace
Celebration," an account of
the celebration held by the Linnean Society of London on July 1st,
1908, this being the fiftieth anniversary of the reading of the joint
paper by Darwin and Wallace on July 1st, 1858. The joint paper is
republished in this volume, and the speeches made by the seven
medallists are recorded. Lent by Dr. S. F. Harmer, F.R.S.

85. "Catalogue of the
Library of Charles Darwin, now
in the Botany School, Cambridge," compiled by H. W. Rutherford, 1908.

86. "Darwin and Modern
Science"; twenty-nine essays in
commemoration of the centenary of the birth of Charles Darwin and of
the fiftieth anniversary of the publication of the "Origin of Species";
edited by Prof. A. C. Seward, M.A., F.R.S.; Cambridge University Press,
1909.

87. Order of the Proceedings
at the Darwin Celebration
held at Cambridge, June 22-24, 1909; with a sketch of Darwin's life,
and eleven plates. Presented by the Syndics of the University Press,
Cambridge.

88. "Christ's College
Magazine," Vol. xxiii, No. 70,
Cambridge, 1909. Darwin Centenary Number. The book is opened
at pp. 222-3, and shows a letter from Darwin to Wallace, April 6th,
1859, after the reading of their joint paper before the Linnean Society
and before the publication of the "Origin of Species."

90. Coloured print of
Christ's College from the street,
about Darwin's time. From R. Ackermann's "History of Cambridge," 1815;
drawn by W. Westall, and engraved by Black. Lent by A. E. Shipley,
Esq., F.R.S.

91. Coloured print of the
Botanic Gardens, Cambridge,
about Darwin's time. From R. Ackermann's "History of Cambridge," 1815;
drawn by W. Westall, and engraved by J. Stadler. Lent by A. E. Shipley,
Esq., F.R.S. The Botanic Garden here shown is the old Botanic Garden of
the University, on the site of which most of the Museums and
Laboratories were built later. The picture shows, in the middle, King's
College Chapel (mentioned by Darwin as one of the things that gave him
most pleasure in Cambridge), the tower of St. Bene't's Church (on the
left), and that of Great St. Mary's, the University Church (on the
right).

92. Portraits of seven
generations of Darwins. Charles
Darwin is the third of the series. To the left are his son George and
grandson Charles; and to the right his father Robert Darwin, doctor of
medicine, his grandfather Erasmus Darwin, author of "Loves of the
Plants," Robert, the father of Erasmus, and William, the grandfather.
Lent by Sir George H. Darwin, K.C.B., F.R.S.

93. Portrait of Darwin as a
boy of seven, with his
sister; reproduced from a small pastel drawing made in 1816 by
Sharples, now in the possession of Miss Wedgwood of Leith Hill Place.
Lent by Horace Darwin, Esq., F.R.S.

94. Portrait of Darwin's
father, Robert Waring Darwin,
M.D., F.R.S., born 1766, died 1846; mezzotint by Thomas Lupton, after
the painting by James Pardon, Shrewsbury; published 1839.

95. A reproduction by Mr.
Dew-Smith of a photograph of
Darwin by Messrs. Maull and Fox, taken about 1854. The copy shown is
from the "Annals of Botany," xiii, 1899; similar reproductions have
appeared in "More Letters of Charles Darwin," 1903, and "Darwin and
Modern Science," edited by A. C. Seward, 1909. A wood engraving of the
photograph was published in Harper's

96. An early portrait of
Darwin after T. H. Maguire.
(Ipswich British Association Series, 1849.) The copy shown is from the Bookman,
Feb. 1909.

97. Two Replicas of the
Linnean Society's
Darwin-Wallace Medal struck in 1908 to commemorate the fiftieth
anniversary of the reading of the joint paper by Darwin and Wallace, at
the Society's meeting on July 1st, 1858. The medal was designed by
Frank Bowcher, Esq. Seven of the medals were awarded in 1908, the first
recipient being A. R. Wallace. Lent by C. E. Fagan, Esq., and B. B.
Woodward, Esq.

98. Electrotype of the
original wax model from which
the Darwin Medal of the Royal Society is reduced. Presented to the
Museum by the late Sir John Evans, P.S.A., Treas. Roy. Soc, Feb. 28th,
1891. The Darwin Medal was first awarded in 1890, and the first
medallist was A. R. Wallace. The medal was executed by Allan Wyon, Esq.

101. Photograph of the
statue of Darwin by Sir J. E.
Boehm, R.A. The statue is situated on the main staircase of the Museum,
and the photograph is reproduced opposite page 7 of this Guide.
Photograph by Mr. H. G. Herring.

102. Photograph of Darwin
taken by Mrs. Cameron about
1868. Lent by Francis Darwin, Esq., F.R.S. This is reproduced, by kind
permission of Mr. John Murray, as the frontispiece of this Guide.

103. Photograph of
Darwin, about 1874, taken by
Major Leonard Darwin, R.E., Pres. R.G.S. Lent by Horace Darwin, Esq.,
F.R.S. This portrait was engraved on wood for the Century
Magazine, January, 1883, and is reproduced in "Life and Letters of
Charles
Darwin," Vol. ii, 1887.

104. Wood engraving by G.
Kruell, 1889, of a photograph
of Darwin by Messrs. Elliott and Fry, 1882. Lent by the Linnean Society
of London.

105. Photograph of Darwin,
enlarged from a negative
taken by O. J. Rejlander about 1870.

Darwin by O. J. Rejlander in 1870 (?); published in Nature,
June
4th, 1874. Presented by Messrs. Macmillan & Co.

107. Three photographs of
Darwin by the London
Stereoscopic Company, taken about 1864.

108. Four photographs of
Darwin by Messrs. Elliott and
Fry, taken in 1882, i.e. the year of his death.

109. Photograph of the oil
painting of Darwin by W. W. Ouless, R.A.,
1875, in the possession of W. E. Darwin, Esq.

110. A half-tone
reproduction of P. Rajon's etching of
the oil painting of Darwin by W. W. Ouless, R.A., 1875, in the
possession of W. E. Darwin, Esq. The copy shown is from the Bookman,
Feb. 1909.

111. Photograph of the oil
painting of Darwin by the
Hon. John Collier, R.A., 1881, in the possession of the Linnean Society
of London. Lent by the Linnean Society.

112. Photograph of Darwin
taken by his son, Major
Leonard Darwin, between 1872 and 1878. Lent by Major Leonard Darwin,
R.E., Pres. R.G.S.

113. Photograph by W. W.
Naunton of the statue of
Darwin by H. Montford, situated in front of the Old Shrewsbury School
(now a Museum and Library).

114. Photograph of the
village of Down, enlarged from a
negative by G. W. Smith, Esq. Lent by Horace Darwin, Esq., F.R.S.

115. Photograph of Darwin's
House at Down. Lent by
Horace Darwin, Esq., F.R.S.

FOSSIL BONES COLLECTED BY
DARWIN.

In Case 11, an upright
table-case standing across the Entrance of
Bay VIII (the third bay or recess on the Eastern side of the Hall
counting from the Huxley statue):—

Fossil bones collected by Darwin in the latter part of the year 1833
and the beginning of 1834, during the voyage of the Beagle.
They
are from the Pampas Formation (Pleistocene) of the Argentine Republic,
and the Pleistocene of Patagonia. Darwin presented the bones to the
Royal College of Surgeons Museum on his return, and descriptions of
them were published by Owen. They are now exhibited here by the
courtesy of the Council of the Royal College of Surgeons.

Equus curvidens,the first fossil teeth of a
horse-like
animal discovered in the New World; bones and teeth of Great Ground
Sloths of the genera Megatherium, Mylodon, and Scelidotherium; bones of Macrauchenia; and skull of Toxodon,
a
large extinct Ungulate, of the sub-order Toxodontia. Darwin records how
he found this particular skull lying in the yard of a farmhouse near
the Sarandis, a tributary of the Rio Negro, where the boys had amused
themselves by throwing stones at it, and pulling out the teeth. He
purchased it, the first discovered relic of the new sub-order, for
eighteenpence. A letter from Darwin to Owen concerning this skull
is
exhibited in Case 1 (No. 6).

BARNACLES AND CORALS
STUDIED BY DARWIN.

In Case 13, a table-case
standing in Bay IX (the second bay or
recess on the Eastern side of the Hall counting from the Huxley
statue):—

Specimens of Cirripedia or Barnacles in illustration of Darwin's
work on that group. Darwin's Monograph on the Cirripedia, published in
1851-1854, is still one of the chief works of reference on this group
of animals. The work was largely based on an examination of
the Museum collection, which therefore contains the type-specimens or
co-types of most of the new species described by Darwin. The specimens
exhibited comprise:—

B. Specimens and drawings illustrating special
discoveries made by Darwin:—Proteolepas, a
maggot-like
Barnacle, of which only one specimen has been discovered, Cryptophialus,
another extremely peculiar form, and the complemental
males of Scalpellum. The great majority of Cirripedes are
hermaphrodite, having both sexes combined in each individual. Darwin
discovered, however, that certain species have minute males, which are
attached like parasites to the hermaphrodite individuals, and to these
he gave the name of "complemental males." In a few species the
separation of the sexes is complete, and the large individuals are
purely female.

C. Specimens described or mentioned in Darwin's work,
with some notes in his handwriting. Particular attention is called to
the series of Balanus amphitrite, a series selected
by
Darwin
himself, with a manuscript of his in which he expresses the difficulty
which he experienced in defining the limits of the species.

Millepores and Nullipores collected by Darwin in 1836 on Keeling
Island, an atoll in the Indian Ocean, 800 miles S.W. of Batavia. The
series shows corals in the fresh state and in various stages of
conglomeration to form the body of the atoll; also some water-worn
coral pebbles. The explanatory account of the specimens is in Darwin's
own handwriting: the writing being in places difficult to decipher, a
printed copy of it is also shown. Darwin's observations on coral reefs
were published in 1842 as the "First Part of the Geology of the Voyage
of the Beagle—The Structure and Distribution of Coral Reefs";
and a second edition was published in 1874.

OTHER SPECIMENS COLLECTED
BY DARWIN, OR STUDIED BY
HIM, OR OTHERWISE CLOSELY CONNECTED WITH HIS WORK.

In Case 6, the North
wall-case in Bay VII, the third recess on the
Eastern side of the Hall counting from the Huxley statue, are shown a
few of the specimens, other than Corals and Fossil Mammals, collected
by Darwin when on the voyage of the Beagle.

(The greater part of the collection of natural history specimens was
deposited with the Zoological Society, and a selection of the Birds and
Mammals was transferred to the British Museum in 1855. The Fishes were
sent to Cambridge, and are now in the University Museum of Zoology. The
fossil bones were sent to the Royal College of Surgeons Museum, and are
shown here in Case 11, on loan
from the College. The fossil Mammal
bones were described by R. Owen in Part 1 of the "Zoology of the
Voyage of H.M.S. Beagle" the recent Mammals by G. R.
Waterhouse in Part 2, the Birds by J. Gould (and G. R. Gray) in Part 3,
the Fishes by L. Jenyns in Part 4, and the Reptiles by T. Bell in Part
5. The Insects were not described in the Beagle reports, but
an account of the new species was written by G. R. Waterhouse, and
published by the Zoological Society.)

116. A selection of Beagle Insects.

117. A small selection of Beagle Reptiles and
Amphibians. The specimens shown are two species of Lizard, a small
Snake, and three tailless Batrachians. Of these last the form known as Rhinoderma
darwinii, first known to science through Darwin's capture of it,
is of particular interest from the exceptionally large size of the
gular pouches of the male, a pair of pouches in the floor of the mouth
which in this species extend far back beneath the skin of the belly,

and within which the eggs undergo their development, the young frogs
emerging from the mouth of the parent on the completion of the
metamorphosis.

118. A small selection of Beagle Birds, namely
three Mocking Birds (Mimus).

119. A small selection of Beagle Mammals,
namely three Opossums and two Murid Rodents.

120. The skin of the Fox
which Darwin killed with a
geological hammer in the island of San Pedro, South Chili,
in 1834. This is the fox of which Darwin writes: "two of the
officers landed to take a round of angles with the theodolite. A
fox (Canis
fulvipes)...was sitting on the rocks. He was so intently
absorbed in watching the work of the officers that I was able, by
quietly walking up behind, to knock him on the head with my geological
hammer." ("Naturalist's Voyage round the World," Ed. 2, p. 280.)

121. Darwin's geological
hammer, probably the one with
which he killed the fox, here shown. Lent by W. E. Darwin, Esq.

122. (In the upper part of
the case.) Darwin's insect
net, with scissor handles. Lent by Sir George H. Darwin, K.C.B., F.R.S.

123. Three fossil
Cephalopods described and figured in
Darwin's "Geological Observations on South America," 1846, plate 5. Nautilus
d'orbignyanus and Baculites vagina were obtained from
the
Upper Cretaceous of Chili, and Ancyloceras simplex from the
Cretaceous of Tierra del Fuego. These specimens were transferred from
the Museum of Practical Geology in 1880.

124. (In the upper left-hand
corner of the case.) The
skull of the Niatu Ox sent to Darwin by Captain Sulivan after the
return of the Beagle. Lent by the Royal College of Surgeons.
The Niatu Cattle of South America show what a great difference in the
chances of survival or extinction may be made by a small difference in
structure. These cattle, owing to the shortness of the muzzle and the
consequent projection of the lower jaw, cannot browse on the twigs and
reeds to which other cattle are driven in times of drought, and they
perish if not fed by their owners. ("Origin of Species," Chap. vii;
"Naturalist's Voyage round the World," Chap. viii, Ed. 2, p. 145.)
Another skull (125), with the
front teeth complete, is shown on the
floor of the case.

126. (On the floor of the
case.) A Porto Santo Rabbit, a breed of
rabbit which in Darwin's opinion had by isolation evolved charac-

ters which distinguished it from the original domestic stock
("Animals and Plants under Domestication," Chap. iv). In 1418 a rabbit
on a vessel travelling from Spain to Porto Santo, near Madeira, gave
birth to young, which were subsequently turned loose on the island,
where, in course of time, they multiplied to such an extent as to
become a pest. In 1861 two of the Porto Santo rabbits were brought
alive to the Zoological Gardens, and it was noticed that these feral
rabbits were, on comparison with English wild rabbits, smaller, more
wild, shy and active, more nocturnal, and that they did not exhibit the
usual blackish grey fur on the upper surface of the tail and the tips
of the ears. Since, further, they refused to mate with English rabbits,
it was urged that by isolation the feral rabbits had evolved characters
not possessed by the original stock. It is now known, however, that the
common rabbit of the countries round the Mediterranean is not the same
as the English rabbit, and an error in the argument was introduced by
instituting a comparison between the Porto Santo rabbit and the English
rabbit, instead of the Spanish rabbit.

127. (On the floor of the
case.) A small selection of
the Ducks studied by Darwin in the course of his work on Domesticated
Animals, and presented by him to the Museum. For Darwin's views on
Domestic Ducks see "Animals and Plants under Domestication," Vol. i,
pp. 290-302.

128. (On the floor of the
case.) A small selection of
the Pigeons studied by Darwin in the course of his work on Domesticated
Animals. See "Animals and Plants under Domestication," Vol. i, pp.
137-235. The birds here shown represent one-third of the Pigeons
presented to the Museum by Darwin in 1867. (A carefully mounted Blue
Rock Pigeon and most of the common breeds of Domestic Pigeon are shown
in Case 18 in the body of the
Hall.)

SPECIMENS ILLUSTRATING
DARWIN'S DISCOVERIES, OR
ILLUSTRATING PASSAGES IN HIS PUBLISHED WRITINGS, MORE PARTICULARLY THE
"ORIGIN OF SPECIES."

(The sequence of the specimens is on the whole based on that of the
chapters in the "Origin of Species," but owing to various
considerations the rule has not been strictly followed. The sixth
edition
of the "Origin of Species" was used in the arrangement of

the series, and the references to the chapters given in the labels
attached to the specimens refer to that edition. The sixth edition,
1872, is the last edition; copies bearing more recent dates are
reprints, differing in pagination, but in no essential respect.)

129. (At the left-hand end
of Case 6.) A skin of a
Peacock Pheasant, Polyplectron malaccense, in which
Darwin
found the clue to the evolution of the single notched "eye" of the
Peacock's tail feather from the paired ocellus such as is found in the
tail feathers of Polyplectron chinquis (also shown). In the
frame marked Case 5, near this
specimen, are shown Peacock feathers
selected and arranged so as to form a graded series, gradation in
characters being, as Darwin pointed out, important evidence in arriving
at an explanation of the origin of highly complex structures. In
connection with these feathers should be studied those of the wings of
the Argus Pheasant in Case 10,
on the opposite side of the Bay, showing
the rows of "eyes" resembling balls in sockets. At the right-hand end
of Case 9 is a photograph (204, lent
by the University Museum
of
Zoology, Cambridge) of the fire-screen made from the feathers of the
Argus Pheasant referred to by Darwin in his observations on the
evolution of ocelli ("Descent of Man," Ed. 2, p. 441).

130. (In the left half of
Case 6.) An Indian Jungle
Fowl, Gallus bankiva, reputed to be the wild ancestral form
of
the domestic breeds of Fowl. ("Origin of Species," Chap. i.; "Animals
and Plants under Domestication," Chap. vii.) Examples of the principal
breeds of Domestic Fowl are shown in Case 21.

131. Blue Rock Pigeon, Columba
livia, reputed
to be the wild ancestral form of all domestic breeds of Pigeon.
("Origin of Species," Chap. i; "Animals and Plants under
Domestication," Chaps. v and vi.) Examples of the principal breeds of
Domestic Pigeon are shown in Case 18.
Attention may here be called to
the large series of Domestic Animals of all kinds exhibited in the
North Hall.

132. Red Grouse of Britain
and Willow Grouse of Norway,
cited by Darwin as a case in which difference of opinion existed
whether the two birds were of distinct species or were local races of
one and the same species. ("Origin of Species," Chap. ii, Doubtful
Species.) In connection with the question here raised may conveniently
be studied the series of Crows in Case 17.
Whether the intermediate
forms there exhibited are regarded as having arisen by the
interbreeding of two distinct species, or whether the two "species"
of Crows are looked upon as dimorphic forms of a single

species, the series is interesting as illustrating the difficulty
in
defining the limits of a species. The Goldfinches also shown in Case 17 illustrate the same difficulty.

133. A series of
thirty-three species of Fresh-water Mussel, Unio,
from North America. An example of a large or dominant genus which
includes a number of very distinct species. ("Origin of Species," Chap.
xiv.) The species of the larger genera in each country vary more
frequently than the species of the smaller genera. ("Origin of
Species," Chap. ii.)

134. (In the upper part of
the case.) A series of shells of Vivipara (= Paludina) of the Pliocene of Slavonia,
arranged to
show
the evolution of ornamented and tuberculated forms in the higher strata
from the smooth forms of the lower strata, in accordance with the views
of Neumayr and Paul, 1875.

135. A series of shells of a
Snail, Helix picta, in
which the colours and markings of the shell exhibit a wide range of
variation within the limits of the species.

136. A series of shells of Neritina
communis. The
colours and markings of the shell exhibit a wide range of variation
within the limits of the species, and, as illustrated by the specimens
in the bottom row, the same shell may show differences of pattern and
colour in its earlier and later parts.

137. A series of shells of Planorbis
multiformis from
the Miocene of Steinheim, showing within the range of the same species
a transition from the usual depressed form of shell to the turret form.
Similar transitions are known in living species of Planorbis.
The
gradation of the forms of Planorbis multiformis in relation
with different horizons is referred to in the "Origin of Species,"
Chap. x.

138. A series of
thirty-three shells of Paludomus (Tanalia) aculeatus, Gmelin, from the streams of Ceylon, showing
the great variation in size, form, sculpturing, and colouring
observable within the limits of the species. Some of the varieties were
formerly held to be distinct species, and the names given to the more
marked of these have been placed under the examples shown.

139. A series of shells from
the Baltic Sea and the
North Sea. The Baltic specimens are shown above the corresponding
specimens from the North Sea. Darwin suggests that possibly the
dwarfing of the shells, admittedly due to the physical conditions of
life, might be inherited for at least a few generations, in which case
the Baltic

specimens would be called a "variety" of the usual form, such as
is found in the North Sea. ("Origin of Species," Chap. ii,
Variability.) Presented by the Riksmuseum, Stockholm.

140. Specimens of the Isopod
Crustacean Tanais or Leptochelia dubia. As one of the perplexing
differences
occurring between individuals of the same species Darwin refers to the
statement by Fritz Müller that in Tanais there are two
forms
of males, one with large pincer-claws, and the other with small claws,
but with the antennae more abundantly furnished with smelling hairs
than in the first kind. ("Origin of Species," Chap. ii.) According
to Müller, whose specimens were collected on the coast of Brazil, the
two forms of males are not connected by intermediate gradations. Recent
investigations on specimens collected at Naples show that intermediate
forms do occur between the "high form" A, and the "low form" B.

141-147. (In the upper part
of Case 9.) Seven series of Butterflies
selected to illustrate the passages in A. R. Wallace's paper on the
Papilionidæ of the Malayan Region (Trans. Linn. Soc., xxv, 1866)
referred to by Darwin in Chap. ii of the later editions of the "Origin
of Species."

141. Some representative or
characteristic species of
Butterflies from the Malayan region, belonging to families other than
the Papilionidæ.

142. Specimens of Papilio
fuscus (P. severus of
Wallace) showing "simple variability." The species occurs in all the
islands of the Moluccas and New Guinea, and exhibits in each of them a
greater amount of individual difference than often serves to
distinguish one species from another.

143. Specimens of Troides
priamus illustrating
"simple variability." In the left upper corner are a male and female
from Amboyna, in which island both males and females are constant.
Below are one male and two different females from New Ireland, whence a
green form of male (not shown here) is also recorded. On the right are
two different males and two different females from New Guinea.

144. Polymorphic females in
Papilionidæ. In the first
column are shown a male and four forms of female of Papilio
polytes, all from the same locality in Ceylon. The second column
shows a male and a "theseus" form of female from Sumatra,
and below these a male, a "theseus" form of female, an
intermediate female, and a "ledebourius" form of female, all
from the Philippine Islands. In

the third column are a male of Papilio ægeus and three
distinct forms of female (not from the same locality). In the fourth
column are examples of seasonal dimorphism in Araschnia levana,
in
which species the second brood differs markedly from the first brood,
and intermediate forms occur.

145. Polymorphic Females in
Papilionidæ (continued).
In the first column are shown a male and two different females of Papilio
memnon from India; in the second a male and three different
females from Java; and in the third column a male and two different
females from Borneo.

146. Series of Papilio
agamemnon illustrating
the local races or sub-species occurring in the different islands of
the Malay Archipelago. The races are distinguished by differences in
size and outline; the differences are tolerably constant in each
locality.

147. Series of Papilio
ulysses illustrating
the local races or sub-species occurring in the different islands of
the
Malay Archipelago. The races are distinguished by differences in the
colour-markings, the outline of the wings, and the size of the patches
of velvety scales on the fore wings of the males; the differences are
constant, each local race being fixed and isolated.

148. (In the upper part of
Case 6.) Examples of male
and female of the Cock-of-the-Rock, Rupicola crocea, a
Parrot, Eclectus cornelia, the Ruff, Pavoncella pugnax,
and a
Bird of Paradise, Cicinnurus regius, showing the
differences
in the appearance of the two sexes. ("Origin of Species," Chap. iv,
Sexual Selection; "Descent of Man," Chap. xiii.) For the aspect of the
Ruff at different periods of the year, see Case 22 on
the West side of
the Hall. Attention may also be directed to the series of Ducks in Case 23.

149. Three male
Stag-beetles, with injuries caused by
the mandibles of other males in fighting. ("Origin of Species," Chap.
iv, Sexual Selection.)

150-156. A series of Birds
in illustration of Darwin's observations
on the plumage of the young in comparison with that of the adults. ("
Descent of Man," Chap. xvi.)

150. House Sparrow, Passer
domesticus. The
adult male is more conspicuous than the adult female (note the dark
throat), and the young in its first plumage resembles the female.

151. Bullfinch, Pyrrhula
europæa. The adult
male is more brilliant than the adult female, and the young resembles
the female in dullness of coloration, but differs in the absence of
black on the top of the head.

152. Amydrus blythi,
a Starling of
Sokotra. The
adult male is less conspicuous than the adult female, and the young
resembles the male.

153. Starling, Sturnus
vulgaris. The adult
male and female are alike, and the young has a first plumage peculiar
to itself.

154. Kingfisher, Alcedo
ispida. The adult male
and female are brilliant and alike, and the young in its first plumage
does not differ from the adults.

155. Red Bishop-bird, Pyromelana
oryx. The
adult male has a brilliant summer plumage, and in the winter is dull
and resembles the adult female, which is the same in summer and winter;
the young resemble the adults in their winter plumage.

156. Oreopyra
leucaspis, a
Humming-bird
of Central America. The adult male differs in coloration from the
adult female; the young male resembles the adult male, and the young
female the adult female.

157. Specimens of the
Elephant-fly, Tabanus
internus, a fly which, by constantly harassing the
Elephant
and
other large mammals, checks undue increase in their numbers. ("Origin
of Species," Chap. xi.)

158. Specimens of the
Screw-worm Fly, Chrysomyia
macellaria. In Paraguay, where the fly is common,
horses, cattle,
and dogs are prevented from running wild and flourishing in a feral
state by the fly laying its eggs in the navel of the new-born young,
with usually fatal results when the maggots hatch out. ("Origin of
Species," Chap. iii, Struggle for Existence.) As an illustration of the
balance maintained in nature, Darwin suggests that if certain
insectivorous birds were to decrease in Paraguay, the parasitic insects
which probably attack the navel-frequenting fly would increase, and the
fly itself would accordingly decrease. The resulting diminished
mortality among the cattle would react on the vegetation, thereby
influencing the number of herbivorous insects, and thus of
insectivorous birds, "and so onwards in ever-increasing circles of
complexity."

159. A copy of the diagram
drawn up by Darwin to
illustrate his views on the evolution of species. The intervals between
the horizonal lines represent large units of time, e.g., a
thousand generations, and the letters A to L at the bottom of the
diagram stand for the several species of a genus occurring at one time
in a country. While some of the species suffer extinction in course of
time, as does D before reaching the period represented by the third
horizontal line

of the diagram; others, such as F, survive unchanged to the end of
the whole period which the diagram is supposed to cover. Other species
again, such as A and I, are continually branching out into divergent
varieties, most of which become extinct; but others persist, and vary
again, until at the end of the whole period (represented by the
uppermost horizontal line of the diagram) there are eight different
species derived from A, and six from I. For a detailed explanation of
the diagram, the visitor is referred to "The Origin of Species," Chap.
iv.

160-165. A series of blind
animals, mostly cave-dwellers. In
instituting a comparison between the blind cave-animals of North
America and Europe, Darwin laid stress on the fact that in each case
the cave-animals are closely related to the animals of the surrounding
country. If the blind animals had been special creations adapted for
cave-life generally, one would have expected a close similarity in the
organisation and affinities of the animals in the New and Old World
caves ("Origin of Species," Chap. v, Effects of Use and Disuse).

160. A Cave-rat, Neotoma
pennsylvanica, from
Virginia, U.S.A. The specimens that live in dark caves are blind, but
on being brought gradually into increasing intensity of light they
slowly acquire a visual perception of objects.

161. Ctenomys fueginus, a burrowing
Rodent of
South America which is frequently blind. Darwin accounts for the
reduction in the efficiency of the eyes as due to disuse, aided perhaps
by natural selection, for the eyes in subterranean passages are not
only useless as organs of vision, but are disadvantageous, in
consequence of their liability to inflammation. Other examples of
burrowing animals many of them partially or totally blind, are shown in
Case 2.

162. Proteus anguinus, a blind
Amphibian of
the Caves of Carniola, Austria.

163. Two blind Cave Fishes
from the United States, Typhlichthys
rosæ and Amblyopsis spelæus.

164. Cambarus pellucidus, a blind
Crayfish
inhabiting the underground waters of the Mammoth Cave of Kentucky.

165. Several species of Anophthalmus, Bathyscia and
other genera of blind Beetles found exclusively in caves.

166. A series of
Dung-beetles, in which the tarsal or
terminal joints of the front legs are wanting. In the beetles in the
top row

the tarsi are wanting in both sexes; in the other species exhibited
they are absent in the male and very minute in the female. Darwin
explains the phenomenon of loss or reduction of the tarsi as due, not
to an inheritance of repeated mutilations, but to the effects of
long-continued disuse ("Origin of Species," Chap. v, Effects of Use and
Disuse). In connection with the disuse of organs in Insects may here be
considered the flightless Beetles of Madeira and other islands (225,
Case 12), in which the wings
have dwindled in size until the power of
flight has been lost.

167. A graded series of
Lizards of the family Scincidæ
showing reduction in the limbs, an illustration of the generalisation
that "natural selection will tend in the long run to reduce any part
of the organisation as soon as it becomes, through changed habits,
superfluous, without by any means causing some other parts to be
largely developed to a corresponding degree." ("Origin of Species,"
Chap. v.)

168. The pelvis and hind
limb bones and claws of a
large Anaconda Snake, Boa murina, an example of
vestigial
structures. ("Origin of Species," Chap. xiv.)

169. (In the upper part of
Case 6.) A Bat, a flying
Squirrel, and a Galeopithecus. Darwin, in his reply
to the
contention that Bats could not have been evolved from a quadruped
animal, because the wings in their early stages of evolution would
present no advantage to the possessor, and would therefore not be
perpetuated by natural selection, instances the Flying Squirrel and Galeopithecus as suggesting how, in the early stages of the evolution of Bats,
the wings were but a parachute, a fold of skin extending between the
fore and hind limbs on each side and between the fingers, and that the
power of flapping this membrane was gradually evolved, and eventually
the capacity for true flight. ("Origin of Species," Chap. vi.)

170. The fourth vertebra of
the neck and the skeleton
of the right fore foot of a Giraffe and an Ox, to show the great length
of the bones in the former animal. The height of the Giraffe is
instanced by Darwin in his reply to Mivart's contention that "natural
selection is incompetent to account for the incipient stages of useful
structures." Darwin argued that in times of dearth any slight
superiority in height would enable a Giraffe to browse upon twigs
inaccessible to others of shorter stature, and the taller animals would
thus be more likely to survive and to perpetuate the small increment in
height. ("Origin of Species," Chap. vii.)

171. (In Case 8, a small black
case on a table at
the end of Bay
VII.) A series of twelve specimens of Polyzoa to illustrate Darwin's
observations on the avicularia and vibracula of these animals.

(The focussing of the microscope is effected by rotating the
eye-piece; the slides are brought successively into the field of the
microscope by rotating the milled wheel at the right-hand side of the
case.)

A. Fredericella sultana, a fresh-water
species, not uncommon in this country, shown to illustrate the
appearance of a Polyzoon in the natural extended position. Each of the
individuals of the colony possesses a circlet of tentacles, the cilia
of which drive minute food-particles into the mouth, which is
surrounded by the tentacles.

In the remaining slides (B-M), the animals are in their retracted
condition. The tentacles (not visible in most cases) lie within the
cavity of the "zoœcium," the term applied to the units or individual
members of the colony. The series illustrates some of the modifications
of the avicularia and vibracula, the evolution of which is discussed in
Chap. vii of the "Origin of Species." There can be no reasonable doubt
that an avicularium is to be regarded as a modified zoœcium, while a
vibraculum is an avicularium whose lower, or movable, jaw has been
prolonged into a bristle-like structure, the "seta."

B. Part of a colony of a species of Bugula, consisting
of branches composed of elongated zoœcia arranged in three or four
transverse rows. The numerous avicularia are readily recognised by
their resemblance to birds' heads. The lower jaw, by means of which the
avicularium can grasp a foreign object, corresponds with the lid or
operculum of an ordinary zoœcium, with which the avicularium itself
corresponds.

This specimen, which, like most of the other slides here shown, has
been lent by the University Museum of Zoology, Cambridge, is of special
interest in being one of the specimens collected by Darwin during the
voyage of the Beagle. It may be surmised that
Darwin refers
to
this species, or to one closely allied to it, in Chap. ix of the
"Naturalist's Voyage round the World," where he says, "Perhaps the most
singular part of their structure is, that when there were more than two
rows of cells [zoœcia] on a branch, the central cells were furnished
with these appendages [avicularia], of only one-fourth the size of the
outside ones," a good illustration of the fact which has often been
noted that the observations made during the Beagle voyage
were
the basis of Darwin's later work.

C and D. Fragments of other species of Bugula, showing
similar avicularia. In D the retracted tentacles and the alimentary
canals of the zoœcia are visible.

E. Beania magellanica, a species in which the
zoœcia are not contiguous, each one bearing a pair of large avicularia
near one end.

F. Bugula reticulata, an abyssal species in
which the avicularia are borne on very long, flexible stalks, and are
extremely variable in size in different parts of the same colony.

G-J. Species of Bicellaria, a genus allied to Bugula.
In
the species here shown the avicularia are
developed to
a remarkable extent, and are extremely variable in size.

G. Bicellaria tuba, showing the greatly
elongated avicularia in situ and separated from the branch.

H. Bicellaria moluccensis. The muscles by which
the lower
jaw of the avicularium is closed are readily visible in this
preparation. The zoœcia, which have lost their tentacles and internal
organs, bear a cylindrical process giving rise to a series of
finger-like spines.

J. Bicellaria pectogemma. The variation in the
size of
the
avicularia is very striking.

K. Flustra (Sarsiflustra) abyssicola,
an example of a
species with an entirely different type of avicularium. The avicularia
are completely in series with the rest of the units of the colony, but
may be distinguished by their relatively gigantic operculum, more or
less spoon-shaped, and corresponding with the lower jaw of the
avicularia of Bugula and Bicellaria.

L. A species of Caberea, showing the thread-like "setæ"
of the numerous vibracula. The "elegant little coralline" referred to
by Darwin in Chap. ix of the "Naturalist's Voyage round the World"
probably belonged to this genus, which is remarkable for the
simultaneous movement of the vibracula of the living colony.

M. A species of Selenaria, in which the vibracula are
larger and the minute teeth borne by the setæ are more obvious than in
L.

172. (In the lower part of
Case 9.) Specimens of the
pelvic and hind
limb bones of the Greenland Right Whale, Balæna mysticetus,
being
three selected from a series of eleven described by Sir John Struthers
in the "Journal of Anatomy and Physiology," 1881. An illustration of
the generalisation that rudimentary (vestigial) parts are apt to be
highly variable, the variability resulting apparently from their
uselessness, natural selection having no power to check deviations in
their structure. ("Origin of Species," Chap. v.)

173. (On the sloping back of
the case, towards the
left-hand end.) Shells of coral-inhabiting Barnacles of the genus Pyrgoma,
in which the small valves that close the opening of the shell are
unusually different in the different species. An illustration of the
contention that unusually developed parts are highly variable. ("Origin
of Species," Chap. v.) In the rock barnacles the valves of the shell
differ extremely little even in distinct genera.

The large specimen on this tablet is figured in Darwin's "Monograph
of the Cirripedia," Vol. ii, pl. 13, fig. 1a.

174. A graded series of
eight males and one female of
the Atlas Beetle, Chalcosoma atlas, showing the extreme
variability of the secondary sexual characters of the male. The
characters in question are the large size of the horns on the head and
thorax, the length of the front legs, and the size of the body as a
whole. ("Origin of Species," Chap. v; "Descent of Man," Chap. x.)

175. A graded series of nine
males and one female of the
Indian Stag-beetle, Odontolabis cuvera, showing the extreme
variability of the secondary sexual characters of the male. The
characters in question are the large size of the head and mandibles,
and in a lesser degree the length of the front legs, and the size of
the body as a whole. ("Origin of Species," Chap. v.)

176. Mustela vison,
a North American Polecat,
instanced by Darwin in reply to an objection that aquatic carnivores
could not have been derived from terrestrial forms because the animals
could not have existed in the transitional state. Darwin points out
that Mustela vison has webbed feet and resembles an otter
in
its fur, short legs and the form of its tail. During the summer it
preys on fish, and during the winter it lives like other polecats on
mice and similar land animals. ("Origin of Species," Chap. vi.)

177-180. Specimens of Saurophagus
sulphuratus, Puffinuria
urinatrix, Cinclus aquaticus and Colaptes
campestris. One
of the great difficulties that Darwin had to contend with in the
elaboration of his theory was the fact that the known cases of adaptive
modifications in their early stages are extremely scarce. The four
birds here shown are mentioned by him as instances in which the
observed alteration of habits might in course of time result in a
gradually improving adaptive modification of certain parts of the body.
("Origin of Species," Chap. vi.)

177. Tyrant Fly-catcher, Saurophagus
sulphuratus, a
bird of South America which at times hovers like a Kestrel, and at
other times dashes into water like a Kingfisher.

178. Puffinuria urinatrix, a Petrel which
in its
habits of diving, swimming and flying resembles the Auks and Grebes
rather than its own relatives.

179. Water-ouzel, Cinclus
aquaticus, a bird
allied to the Thrushes, yet differing markedly from them in its habit
of diving in water.

180. Colaptes campestris,
a Woodpecker,
possessing the long straight beak, the usual arrangement of the toes,
two forward and two backward, for grasping boughs of trees, and the
stiff tail feathers to support the body against a tree trunk, yet
living on the plains of La Plata where hardly a tree grows, and making
its nest in holes in banks.

181. Swim-bladder of a
Conger Eel and Lungs of a
Monkey. The swim-bladder of Fishes and the lungs of the higher
Vertebrates, occupy the same position in the body and are developed in
the same manner, but the one serves for flotation and the other for
respiration. Darwin points out how a change of function may have been
brought about in an organ by two organs in the body
subserving
for a time the same function, which function is gradually transferred
from the first or older organ to the newer, and ultimately confined to
the newer. He instances the case of the Dipnoan fishes, animals which
use the swim-bladder for respiratory purposes alternately with the
gills, and thus indicate a transition to the higher Vertebrates in
which functional gills do not occur, and the lung is the sole organ of
breathing. ("Origin of Species," Chap. vi.)

182. Two embryos of the
Fowl, incubated about four
days, and an explanatory sketch, showing the transient gill-slits which
point to descent from water-breathing ancestors. ("Origin of Species,"
Chap. vi.)

183. Dissections of eyes of
three Cephalopods and a
Vertebrate (Horse). In reply to Mivart, who instanced, as one of the
difficulties in the way of acceptance of the theory of natural
selection, the similarity of structure in the eyes of animals so
remotely related as Cuttle-fishes and Vertebrates, Darwin pointed out
that though there is a general resemblance between the eyes, there are
very fundamental differences. ("Origin of Species," Chap. vi.)

The lens in the eye of the Cuttle-fish is a hardened secretion of
the skin, whereas that of the Vertebrate eye is composed of cells of
the skin which have coalesced and become transparent. The retina of the
Cuttle's eye is directly transformed from the epidermal layer of the
skin, whereas that of the Vertebrate eye is developed from

the brain as a hollow outgrowth, the outer part of which becomes
inpushed and converted into a cup. Moreover, the manner in which the
eye of Sepia (C) has probably been evolved from a simple,
nearly-closed pit, such as occurs in Nautilus (A), is
indicated in the condition found in Ommastrephes (B). In Nautilus there is no lens; in Ommastrephes a lens is present,
but
it is only partially covered over by a layer of skin; while in Sepia this layer is complete and transparent, and is known as the cornea.

184. Sesarma mülleri and Ocypoda
arenaria, two crabs belonging to different but related families,
and both adapted for living out of the water, although the arrangements
for admitting air to the gill-chamber for the purpose of aerial
respiration are different in the two cases. ("Origin of Species," Chap.
vi.) In Sesarma mülleri the carapace can be raised behind
so
that a slit-like opening into the gill-chamber appears above the last
pair of legs; in Ocypoda arenaria there is an opening,
fringed
with hairs, between the third and fourth pairs of legs on each side of
the body. The conclusion to be drawn from these facts is that the
capacity for breathing air has been acquired independently in the two
crabs, the common ancestral form being capable of aquatic respiration
only (Fritz Müller).

185. A small series of
fruits and seeds as an
illustration of Darwin's remark that the same end may be gained by the
most diversified means. The end to be gained in the present instance is
the conveyance of the seeds to a distance from the parent plant, and
this is effected by a modification of the seed-coat or the carpel into
a fluff (e.g. 1 and 2) or a membrane (e.g. 3),
such
as will enable the wind to carry the seeds to a distance before they
reach the ground, or into hooks (e.g. 4, 5, and 6),
which,
by
entanglement in the fur of passing animals, will result in the seeds
being taken to a distance before they are dislodged. Or the carpels
may, on drying, dehisce with such violence as to eject the seeds to a
distance (e.g. 7 and 8), or they may become sticky when
wet
so
as to cling to the bodies of passing animals (e.g. 9). Or
the
fruits may be of such a nature that, at all events, in a proportion of
cases, the seeds are protected from the action of the digestive juices
of animals which eat them (e.g. 10 and 11). ("Origin of
Species," Chap. vi.) A much more extensive series of specimens
illustrating the means of dispersal of fruits and seeds is exhibited in
the Botanical Gallery.

186. A small series of
Lamellibranch shells, selected
to illustrate Darwin's remark on the diversity in the form of the hinge
and its teeth; an example of the same purpose being served in different

ways in more or less closely related animals. ("Origin of Species,"
Chap. vi.)

187. Examples of Insects
which escape falling a prey to
birds and lizards by their resemblance to decayed leaves, twigs and
spines. Darwin's reply to Mivart's contention that "as the minute
incipient variations will be in all directions, they must
tend
to neutralise one another," is to the effect that, "assuming that an
insect happened to resemble in some degree a dead twig or a decayed
leaf, and that it varied slightly in many ways, then all the variations
which rendered the insect at all more like any such object, and thus
favoured its escape, would be preserved, whilst other variations would
be neglected and ultimately lost; or, if they rendered the insect at
all less like the imitated object, they would be eliminated." ("Origin
of Species," Chap. vii, Miscellaneous Objections.) Numerous other
instances of Protective Resemblance are shown in Cases 7, 14, 24, and 25.

188. Beak of Duck and
"whale-bone." The baleen or "whalebone" of
Whales consists of a great number of laminæ or plates
of a horny material, which fray out at the edge into bristles and form
an efficient strainer. A piece of the baleen of the Humpbacked Whale, Megaptera
boops, is shown on the floor of this case. In answer to Mivart's
question, "How to obtain the beginning of such useful development,"
Darwin referred to the efficient straining apparatus of the beak of the
Shoveller Duck, and pointed to the beak of the Common Duck as an
illustration of the manner in which the evolution of such a useful
apparatus may have begun. ("Origin of Species," Chap. vii.)

189. Common Cuckoo, Cuculus
canorus, and a
clutch of eggs, including a Cuckoo's egg, taken from the nest of a
White-throat. The Cuckoo's eggs are small for the size of the bird;
they are laid singly in strange nests, and the young Cuckoo, shortly
after hatching, ejects its foster-brothers from the nest. Darwin
explains at some length how the habits of the Cuckoo, at first probably
casual, may have become regular and intensified by natural selection.
("Origin of Species," Chap. viii.)

190. Cow-bird, Molothrus
bonariensis, an
American bird related to the Starlings rather than to the Cuckoos, but
having the habit of laying its eggs in the nests of other birds. It
lays several eggs in the strange nest, and thus has not perfected its
parasitic habit to the same degree as has the Cuckoo, or even its own
relative, Molothrus pecorus, which lays but a single egg in
the nest, and thus insures

abundance of food for its offspring. ("Origin of Species," Chap.
viii.)

A large series of eggs of the Cuckoo and of Molothrus is
shown on the West Side of the Main Staircase.

191. A series of nests of
Hymenoptera, leading up to
the exquisitely economical honey-comb of the Hive Bee, in which, for a
given size of cell, the expenditure of wax in the manufacture of the
walls is reduced to a minimum, the cells being not only hexagonal in
section, with single walls dividing adjacent cells, but they are
disposed back to back in two layers in such a way that the three
pyramidal faces of the end of one cell are walls common to three
adjacent cells of the other layer. ("Origin of Species," Chap. viii.)
The examples shown are a nest of the Humble Bee and those of two
species of Polistes, a piece of the honey-comb of the Hive
Bee, and an enlarged model of four of the cells.

192. Examples of
melanic and albino Mammals.
Occasionally there occurs in individual cases an abrupt departure from
the usual coloration of a species, the colour in these cases being
either very intense or even black—melanic form, or else very pale or
white—albino form. ("Origin of Species," Chap. ix.) Numerous examples
of melanic and albino animals are shown in Cases 16 and 15.

193. A small series of bones
of the fore limb of
Horse-like Ungulates showing how, by the loss of the fifth digit and
the shortening of the second and fourth, a form like Hyracotherium,
of the Eocene, may have given rise to one like Hipparion, of
the Pliocene; and how, by a still further reduction of the
second and fourth digits to slender splint-bones, the foot of the
modern Horse may have been evolved. Darwin suggests that the Tapir,
with four toes on the fore limb, though not a direct survival of the
ancestor of the Horse, is not very different from the common ancestor
of the Tapir and Horse. ("Origin of Species," Chap. x.) For a more
extensive series of remains illustrating the ancestry of the Horse the
visitor is referred to one of the middle cases in the North Hall. A
series of remains illustrating in like manner the line of evolution of
the Elephant is on view in the Geological Department.

194. Nautilus, an
extremely ancient Cephalopod
surviving to the present day almost unchanged in character. ("Origin of
Species," Chap. xi.)

195. Lingula,
an extremely
ancient type of
Brachiopod surviving to the present day almost unchanged in character.
("Origin of Species," Chap. xi.)

196. Trigonia, a
Mesozoic genus which has
escaped extinction. The existing species are confined to the Australian
seas; the range of the fossil forms is, with the exception of those
found in the Tertiary rocks of Australia, from the Lias to the
Cenomanian (Upper Cretaceous). ("Origin of Species," Chap. xi,
Extinction.)

197. (In the lower part of
the case.) Specimens of Lepidosiren, Polypterus, and Lepidosteus, solitary modern
representatives of groups which flourished in past geological periods.
Darwin speaks of these as "living fossils," surviving in fresh waters,
where competition is less severe than elsewhere. (It is not clear
whether by "Lepidosiren" Darwin was referring to the Lepidosiren
paradoxa of South America or the Protopterus annectens of
Africa, long known as Lepidosiren annectens both are
therefore shown.) Ornithorhynchus, the
Duck-bill Platypus,
is
another example of Darwin's "living fossils." ("Origin of Species,"
Chaps. iv and xi.)

198. The Tuatara of New
Zealand, Sphenodon
punctatus, as an illustration of the
imperfection of the
geological record. No remains of members of the family Sphenodontidæ
are found later than the Jurassic period, yet Sphenodon is
living at the present day.

199. Cast of Archæopteryx
macrura, from
the
Lithographic Stone (Lower Kimmeridgian) of Eichstädt, Bavaria, as an
illustration of the imperfection of the geological record. Archæopteryx was not known at the time the first edition of the "Origin of
Species" appeared; in the later editions Darwin observes (Chap. x) that
"not long ago palæontologists maintained that the whole class of
birds came suddenly into existence during the Eocene period," and
remarks that the wide interval between birds and reptiles has now been
partially bridged over in the most unexpected manner (Chap. xi).

Particularly impressive as an illustration of the imperfection of
the geological record is the fact that the Solenhofen quarries have
been worked for some two hundred years, and yet only two specimens of Archæopteryx have been discovered, one described in 1862 and the other in 1884.
The actual specimen of which the cast is here shown is in the
Geological Department of the Museum; the later discovered specimen is
in the Berlin Museum.

200. A small series of
Trilobites; an example of a
group of animals becoming abruptly extinct at the close of the
Palæozoic period. ("Origin of Species," Chap. xi.)

201. A small series of
Ammonites; an example of a group
of animals becoming abruptly extinct at the close of the Mesozoic
period. ("Origin of Species," Chap. xi.)

202. A blood-sucking Bat or
Vampire, Desmodus
rotundus, one of the animals which determine
the existence of the
larger naturalised quadrupeds in several parts of South America.
("Origin of Species," Chap. xi, Extinction.)

203. Some remains of the
great extinct Armadillo, Glyptodon,
of the Pleistocene of South America, for comparison with the
exoskeleton of the recent Peba Armadillo; an illustration of the
succession of the same types of animal in the same areas. ("Origin of
Species," Chap. xi.) In his autobiography Darwin mentions that during
the voyage of the Beagle he had been deeply impressed by
discovering in the Pampas formation great fossil animals covered with
armour like that on the existing Armadillos. He could only explain the
facts on the supposition that species gradually became modified, and it
was this supposition, supported by numerous other items of evidence
accumulated on the voyage, which gradually ripened into his theory of
the evolution of species by natural selection. ("Life and Letters,"
Vol. i, p. 82.)

204. Photograph of the
fire-screen made from the
feathers of the Argus Pheasant referred to by Darwin in "Descent of
Man," Ed. 2, p. 441. Lent by the University Museum of Zoology,
Cambridge. (See observations on specimen 129.)

205. (In Case 12, Bay IX.)
Specimens of Porcellio
scaber from New Zealand. Porcellio scaber is a
Woodlouse
extremely common in Britain, and of wide distribution. In New Zealand
it is especially abundant around buildings and in greenhouses, but is
rarely met with in the native bush. The evidence points to the
conclusion that the species has been introduced into New Zealand by the
agency of man. ("Origin of Species," Chap. xi.)

206. Cancer
novæ-zealandiæ, a crab of New
Zealand, closely related to the edible crab of Britain, in illustration
of the remark of Dana's quoted by Darwin ("Origin of Species," Chap.
xii):—"It is certainly a wonderful fact that New Zealand should have a
closer resemblance in its Crustacea to Great Britain, its antipode,
than to any other part of the world." The remark refers particularly to
the genera Cancer and Portunus.

207-212. Ocean-borne seeds
collected in various parts of the world,
as examples of one of the natural methods by which the flora of an
oceanic island becomes established. ("Origin of Species," Chap. xii,
Means of Dispersal.)

207. Drift seeds collected
by Dr. Guppy on the beach of
the Solomon Islands, in the Western Pacific.

208. Drift seeds collected
on the beach of the Caroline
Islands, in the Western Pacific.

209. Drift seeds collected
on the beach of the Admiralty
Islands, New Guinea, during the Challenger Expedition.

210. Four kinds of seeds
picked up on the beach of
Cocos Island, and presented by Dr. F. Wood-Jones, 1909. There are no
plants on the island producing seeds like these. Seeds similar to these
and picked up at the same time have been germinated artificially, and
the explanation why the plants have not yet established themselves on
the island is that the seeds are not thrown sufficiently high up the
beach to find soil for germination.

211. Two kinds of seeds
picked up on the beach of Cocos
Island, and presented by Dr. F. Wood-Jones, 1909. These are seeds of
plants which grow on the island, and it is thus uncertain whether they
are drifted specimens or not. The seeds by which the species were
originally introduced were evidently sea-borne from a distance.

212. Molucca Beans (Entada
sp.), seeds of a
purely tropical plant picked up on the British Coast. The single
specimen in the upper box was found on the Cornish Coast near the
Lizard, the other four were collected on the Orkney Islands. They were
probably brought from Tropical America by the Gulf Stream.

213. Figure of the foot of a
Red-legged Partridge (Caccabis
rufa), with a clod of dry earth adhering. (Proc. Zool. Soc,
1863.)
After the earth had been kept for three years, Darwin broke it up and
watered it, and obtained no less than 82 young plants from the seeds
contained. He points out how seeds in such accumulations of mud and
earth may be carried from one country to another by birds in the course
of their migrations. ("Origin of Species," Chap. xii.)

214. Hooked fruits of Acæna
elongata. Darwin
writes:—"In certain islands not tenanted by a single mammal, some of
the endemic plants have beautifully hooked seeds; yet few relations are
more manifest than that hooks serve for the transportal of seeds in the
wool or fur of quadrupeds. But a hooked seed might be carried to an
island by other means; and the plant then becoming modified would form
an endemic species, still retaining its hooks." ("Origin of Species,"
Chap. xiii.) In this connection the seeds (or, more correctly, the
fruits) of the rosaceous plant Acæna are interesting as
having frequently been found adhering to the feathers of the Albatross,
which may thus be a means of introducing the plant into oceanic islands.

215. Seeds taken from the
crop of Pigeons (a) in the
Admiralty Islands, and (b) in the Solomon Islands. The crop is a part
of the alimentary tract in the lower region of the neck of a bird in
which food is stored until it is passed on to the gizzard. No digestion
takes place in the crop, and seeds may be stored in it unchanged for
many hours, during which the bird may fly or be blown in a gale from a
continent to a distant island. The accidental death of the bird on
arrival might well lead to the seeds germinating and thus establishing
on the island plants previously unknown there. ("Origin of Species,"
Chap. xii, Means of Dispersal.)

216. (On the shelf in
the lower part of the
case.) A Double Coco-nut or Coco-de-mer, Lodoicea seychellarum.
Double
Coco-nuts are well known in consequence of their being brought home by
sailors as curiosities. They are found floating in all parts of the
Indian ocean, but the plant itself lives only in the Seychelles
Islands. The floating nuts were known to travellers long before the
Seychelles were discovered. Recent examination of floating specimens
shows them to be hollow, and incapable of germination, so that as an
example of the spread of plants by means of the sea the case is not a
good one. On the other hand the Coco-nut, Cocos nucifera, is
equally common, or more so, on the surface of the ocean, and those cast
up on distant islands germinate readily.

217. Two ice-borne stones
(erratics) from the Boulder
Clay of Norfolk. Darwin comments on the fact that since icebergs can
carry stones and deposit them at a distance, it is at least possible
that they may carry also seeds of plants from a mainland and leave them
on some distant island in a condition still capable of germination.
("Origin of Species," Chap. xii.)

218. Dragon-flies of three
species, caught at Cocos
Island and presented by Dr. F. Wood-Jones, 1909. At certain times of
the year, generally after a North wind, dragon-flies are very numerous
on the atoll. Yet none of them have been bred on the island; all are
immigrants from some mainland, the nearest of which is several hundred
miles away. Dragon-flies cannot breed on the island because there are
no open tracts of fresh water in which the larval stages of the
life-history may be passed.

219. A Locust, Acridium
peregrinum, one of the
locusts mentioned by Darwin as swarming over the island of Madeira in
1844. ("Origin of Species," Chap. xii, Means of Dispersal.) The
importance of such visits, Darwin points out, lies not only in the
devastation

of the herbage, but in the introduction of new kinds of plants
arising from undigested seeds dropped on the island by the locusts.

220. A Locust, Acridium
peregrinum, one of the
swarm that visited Las Palmas, Grand Canary, in 1908. Fifty tons were
killed and paid for by weight, and it was estimated that this
constituted only one-fourth of the swarm. Allowing 15 specimens to the
ounce, there would be about 107,500,000 specimens in the total of 200
tons.

221. Dytiscus and Colymbetes,
water-beetles
such as might be instrumental in the conveyance of fresh-water molluscs
to distant islands. Darwin speaks of Dytiscus caught with
the
Fresh-water Limpet, Ancylus, adhering to it, and he records
the capture of a Colymbetes on the Beagle at a
distance of forty-five miles from the nearest land. ("Origin of
Species," Chap. xiii, Fresh-water Productions.)

222. Shells of the
Fresh-water Limpet, Ancylus fluviatilis. Darwin
mentions the possibility of the spread of
this
and other fresh-water molluscs by their adhering to water-beetles and
ducks, which may fly across the sea to distant parts. ("Origin of
Species," Chap. xiii.)

223. Shells of three species
of Cyclostoma, land
molluscs with an operculum or lid which so effectually closes the mouth
of the shell that the animal is not injured by immersion in sea-water.
Entangled in drift-wood, the animals may float to distant parts, and
may establish themselves on any island upon which they may be cast up.
("Origin of Species," Chap. xiii.)

224. Shells of the Garden
Snail, Helix aspersa, and
the Edible Snail, Helix pomatia. These molluscs,
though not
provided with an operculum, close the mouth of the shell at certain
times of the year by an epiphragm, a secretion which hardens in contact
with air. Darwin ascertained by experiment that the Edible Snail, when
thus sealed, was uninjured by immersion in sea-water for twenty days.
("Origin of Species," Chap. xiii.)

225. A selected series of
flightless Beetles from
Madeira, Darwin accounts for the occurrence of flightless beetles on
oceanic islands as due to natural selection combined probably with
disuse of the wings. The individual insects which use their wings to
any great extent will be liable to be blown off the island and
destroyed at sea, whereas those which, through indolence or through the
wings being less perfectly developed, venture less in the air will
remain on the island

and perpetuate the deficient mechanism of flight. ("Origin of
Species," Chap. v, Effects of Use and Disuse.)

In some island beetles, e.g., Blaps gages, in
the top
row,
the wing-covers are fused together. ("Origin of Species," Chap. xiii.
Inhabitants of Oceanic Islands.)

226. Specimens of Mellissius
eudoxus, of St.
Helena, a Beetle of interest in being an apterous species of the family
Dynastidæ, the other members of which are winged.

227. Four species of Beetles
of the sub-family
Ectennorhinides, which includes numerous flightless beetles found in
oceanic islands, and a single continental form, Brachyxystus
subsignatus, which is winged.

228. A series of endemic
land shells of Madeira, in
illustration of Darwin's remark that "Madeira is inhabited by a
wonderful number of peculiar land shells, whereas not one species of
sea shell is peculiar to its shores." ("Origin of Species," Chap. xiii.)

229. Five species of Bats
from Oceanic Islands. Darwin
notes that although terrestrial mammals do not occur on oceanic
islands, bats are found, and in many instances they are peculiar to an
island or a group of islands. The explanation is that the ancestors of
the island bats were stragglers from the mainland, carried probably
during a gale, and that their descendants have gradually assumed their
present distinctive characters in relation to their surroundings.
("Origin of Species," Chap. xiii.) Of the specimens shown, Pteropus
rubricollis and Pteropus vulgaris are endemic in
Mauritius and Bourbon, Pteropus psilaphon occurs only in the
Bonin Islands, Pteropus keraudreni insularis is peculiar to
the
Caroline Islands, and Notopteris macdonaldi to the Viti
Archipelago.

230. A series of Black
Grosbeaks peculiar to the
Galapagos Islands, and first discovered by Darwin during the voyage of
the Beagle. Darwin noted that in several cases
different
species inhabited different islands of the archipelago, and he further
remarked that the nearest relatives of these birds are to be found on
the mainland, which one would hardly expect to be the case had the
endemic species of the islands been special creations instead of
modified descendants of birds which had immigrated from the mainland.
("Origin of Species," Chap. xiii.) In his autobiography Darwin states
that it was the peculiarity of the Galapagos fauna, among other things,
that first influenced him to question the immutability of species, and
started a train of thought which found

231. A series of Frogs and
Tree-frogs from Madeira, the
Azores, Mauritius and New Caledonia. ("Origin of Species," Chap. xiii,
Absence of Batrachians on Oceanic Islands.) The statement that "frogs
have been introduced [i.e. by man] into Madeira, the Azores,
and Mauritius, and have multiplied so as to become a nuisance" does
not, except in the case of the Azores, appear to be supported by
evidence. The Rana esculenta found in Madeira is a
widely-distributed frog of Europe, Asia, and North Africa, and the
variety of Tree-frog found in Madeira (Hyla arborea
meridionalis) is
a form common in N.W. Africa. Frogs introduced into the island by man
would be more likely to have been brought in by the Portuguese than by
the Moors, and one would therefore expect rather a Portuguese variety
of Tree-frog than the African. The same Tree-frog also occurs in the
Canary Isles. The Frog of Mauritius (Rana mascariensis)
occurs
also in Madagascar, the Seychelles, and other islands, and there is no
evidence of its introduction by human agency. On the other hand the
Tree-frog of New Caledonia has been definitely ascertained by Layard to
have been brought in from Australia.

232. Galaxias attenuatus,
quoted by
Darwin as an important case of a fish occurring in the fresh waters of
parts of the world as widely remote as Tasmania, New Zealand, Falkland
Islands, and the mainland of South America. ("Origin of Species," Chap.
xiii, Geographical Distribution, Fresh-water Productions.) Recent study
of the family Galaxiidæ has shown that, as in the case of the
Salmonidæ, the fishes are marine fishes of which some have adopted a
purely fresh-water habit. Galaxias attenuatus, however,
although found in brackish and fresh water, breeds in the sea, and its
wide distribution is therefore less remarkable than was formerly
supposed.

233. A small series of
Alpine plants in illustration of
Darwin's remark on the similarity of the mountain plants of distant
parts of the world, and the absence of such plants from the vast tracts
of low ground between. ("Origin of Species," Chap. xii.) Saxifraga
nivalis and Saxifraga rivularis occur on the mountains
of
Europe, Asia and America, Gentiana verna on the mountains of
Europe and Asia, and Gentiana nivalis on those of Europe and
America; yet, except in arctic regions, these plants do not grow below
two or three thousand feet above the sea level.

illustrating the generalisation that vestigial structures, probably
useless to the possessor, are of value as indicating affinity with
animals in which the parts are well developed. The bones of the second
and fifth digits are wanting in the Ox; in the Roebuck and Fallow Deer
they are present as vestiges, and these vestiges serve to show the
affinity that exists between the ruminants and the "pachyderms."
("Origin of Species," Chap. xiv.)

235. Lower jaws of
various Marsupials, showing
the inflection of the angle, which, prevailing as it does throughout
many and different species which have very different habits of life, is
valuable evidence of descent from a common ancestor. ("Origin of
Species," Chap. xiv, Classification.)

236. Skulls of the
Viscacha and Phascolomys, showing
general resemblance. These animals are cited by Darwin ("Origin of
Species," Chap. xiv) in illustration of G. R. Waterhouse's
generalisation that when an animal of one group exhibits affinity with
another group, the resemblances are general and not special. The
Viscacha, for instance, resembles no Marsupial in particular, but
Marsupials generally, and the conclusion to be drawn is that the
Viscacha has departed from the ancestral form common to the Rodents and
Marsupials to a less extent than have other Rodents. Similarly with
regard to the Marsupial Phascolomys, the Wombat, in its
relation with the Rodents. Darwin observes, however, that "it may be
strongly suspected that the resemblance is only analogical, owing to
the Phascolomys having become adapted to habits like those
of
a Rodent."

237. Electrical Organs
in Fishes. Darwin mentions
the occurrence of electrical organs in fishes as one of the
difficulties in the way of accepting his theory, because the fishes
possessing them are not near relatives; because the electrical organs
occur in different parts of the body, and differ in the arrangement of
the plates, and in the nerve supply; and because it is difficult to see
by what graduated steps these organs have been developed in each
separate group of fishes, the organ being of no utility for defensive
or offensive purposes until fully formed. ("Origin of Species," Chap.
vi.) The specimens shown are the Electric Cat-fish, Malopterurus
electricus; Electric Eel, Gymnotus electricus; Electric
Ray, Torpedo hebetans; and Skate, Raia batis.

238. Examples of Insects of
two related families of
Hymenoptera to show that organs that are constant in form in one family
may be of diverse forms in another. ("Origin of Species," Chap. xiv.) In

the upper specimens, of the family Ichneumonidæ, the antennæ are
constant in structure, being long and whip-like. In the lower
specimens, of the family Tenthredinidæ, the antennæ differ much, and
the differences are of subordinate value in classification.

239. Examples of
closely allied Insects differing
more in their larval than in their mature stages—three species of Shark
Moth (Cucullia), and two species of Dagger Moth (Acronycta),
with the caterpillars of each. ("Origin of Species," Chap. xiv.)

240. A Leptalid
Butterfly, Moschnoneura
methymna, bearing a mimetic resemblance to an Ithomiine
Butterfly, Scada phyllodoce.Both occur in the same parts of
South
America. The two Butterflies are not closely related, a detailed
comparison showing that the resemblance is one of shape and colour
mainly. The mimicking Butterfly (Moschnoneura methymna)
differs
considerably in appearance from its relatives, a typical example of
which, Pseudopieris nehemia, is here shown for comparison.
The
Ithomia is distasteful to predaceous birds, and the Leptalis is
supposed to enjoy a freedom from persecution by its resemblance to the
Ithomia. The case is instanced by Darwin as one in which "close
external resemblance does not depend on adaptation to similar habits of
life, but has been gained for the sake of protection." ("Origin of
Species," Chap. xiv, Analogical Resemblances.) Numerous other instances
of such protective resemblance are shown in Case 7.

241. A series of Wasps
and Bees, insects that are
avoided because of their stings, mimicked by Flies, Moths, Beetles and
Neuropterous insects not provided with such weapons. ("Origin of
Species," Chap. xiv.) Of particular interest are the two Beetles in the
top row, the hinder patches of orange and black being situated on the
abdomen in Hesthesis, and on the elytra in Tragoceras.
Other
instances are shown in Case 7.

242. Boring Molluscs,
showing similarity of
external form. The specimens to the right (Petricola
pholadiformis and Coralliophaga coralliophaga)are closely
related
molluscs which resemble respectively the genera Pholas and Lithodomus (specimens to the left), although they are not related to these
genera, and although there is no close affinity between Pholas and Lithodomus. ("Origin of Species," Chap. xiv.)

243. A Mouse, a Shrew
and an Antechinus, belonging
respectively to the Rodentia, Insectivora and Marsupialia, as examples
of unrelated animals having the same general appearance. The
resemblance is attributed to adaptation for similarly active move-

ments through thickets and herbage, and concealment from enemies.
("Origin of Species," Chap. xiv, Analogical Resemblances.)

244. Skulls of Dog and
Thylacine, animals belonging to
the Carnivora and Marsupialia respectively, to show the general
resemblance in the teeth, attributable to the carnivorous habits of the
two animals. The resemblance is a general one only; a detailed
comparison of the teeth shows important differences. ("Origin of
Species," Chap. xiv, Analogical Resemblances.)

245. Diagrams of the
Skeleton of the Fore Limb of
Reptiles, Birds, and Mammals, showing that however different the habits
of life of these animals, the fundamental type of construction of the
limb-skeleton is the same in all. ("Origin of Species," Chap. xiv.) The
humerus is coloured blue, the radius and ulna red, the carpal bones
green, and the metacarpal bones and the phalanges yellow. Equivalent
digits are denoted by similar numerals. Actual specimens of these limbs
are to be seen in the cases on the opposite side of the Hall. "How
inexplicable is the similar pattern of the hand of a man, the foot of a
dog, the wing of a bat, the flipper of a seal, on the doctrine of
independent acts of creation! How simply explained on the principle of
the natural selection of successive slight variations in the diverging
descendants from a single progenitor!" ("Animals and Plants under
Domestication," Chap. i.)

246. Preparations of the
mouth-parts of a Beetle, a
Sphinx Moth and a Bee, with diagrammatic sketches, to show how
remarkably different in size and shape are the organs for sucking and
biting which have been formed by modification of the mandibles and two
pairs of maxillæ. ("Origin of Species," Chap. xiv, Morphology.)

247. The wild Chrysanthemum
of China, Pyrethrum
sinense. This is the wild plant from which all the cultivated
varieties known as "Chrysanthemums" have by assiduous cultivation and
artificial selection been derived. ("Animals and Plants under
Domestication," Chap. xi.)

248. Primrose and Purple
Loosestrife. The flowers of
the Primrose are of two kinds, one with high stigma and low anthers,
and the other with low stigma and high anthers. Darwin, by a series of
experiments, found that better seed is produced by pollinating a high
stigma flower with pollen from high anthers, and a low stigma with
pollen from low anthers, than is produced by pollinating a stigma from
anthers at a different level to itself. (Journ. Linn. Soc. 1862.)
Darwin also discovered that in the Loosestrife

(Lythrum) the stigma and anthers occur at three
levels in
different flowers. (Journ. Linn. Soc. 1864.) See also specimens in Case 19.

249. (In the lower part of
the left-hand half of the
case.) A Sea Iguana, Amblyrhynchus cristatus, a lizard of
the
Galapagos Archipelago, which lives partly on the sea shore and partly
in the sea. It is sluggish in its movements, and feeds on sea-weed.
("Naturalist's Voyage round the World," Chap. xvii.)

250. A hybrid between the
Common Pheasant, Phasianus
colchicus, and the Ring-necked Pheasant, Phasianus
torquatus. This
hybrid is cited by Darwin as one of the few hybrids that are fertile.
("Origin of Species," Chap. ix, Degrees of Sterility.) Many other
examples of Pheasant hybrids are shown in the North Hall.

251. A female Pheasant, Phasianus
colchicus, partly
albino, assuming male plumage. Presented by H.R.H. the Prince of Wales,
1909. Cases of female birds exhibiting male characters, such as long
tail-feathers, hackles, comb, spurs, voice, and pugnacity, are
instanced by Darwin in "The Descent of Man," Chap. viii. In most cases
the phenomenon is associated with old age, or with disease of, or
injury to the generative organs.

SPECIMENS ILLUSTRATING
DARWIN'S RESEARCHES ON PLANTS.

In Case 19, a table-case
near the Owen statue, is exhibited a series
of models, drawings and specimens illustrating the Fertilisation of
Flowers. Instances are given of flowers cross-pollinated by the wind,
and by insects; flowers in which self-pollination is impossible because
the anthers and stigma of the same flower ripen at different times;
flowers in which there are differences in the height of the anthers and
stigma in different flowers of the same species, as Primula and Lythrum; and flowers in which cross pollination by insects
is
favoured by special floral mechanisms, as the Sage and Orchids. The
modern development of the study of this subject was initiated by
Darwin's investigations, published in "The Various Contrivances by
which Orchids are fertilised by Insects," 1862, and "The Effects of
Cross and Self Fertilisation in the Vegetable Kingdom," 1876.

In Case 20, a table-case
near the last, is exhibited a series of
models, drawings and specimens of Insectivorous Plants, such as the
Bladderwort, Pitcher Plant, Butterwort, Sundew and Venus' Fly-trap.
Darwin's book, "Insectivorous Plants," 1875, contains the first
detailed account of the remarkable method of nutrition characteristic
of these plants. A copy of the book is shown in Case 3.